Flake8 fixes

16 files changed, 294 insertions, 330 deletions

diff --git a/lib/spack/llnl/util/lock.py b/lib/spack/llnl/util/lock.py
index e1f5b4878a..bef20025ba 100644
--- a/lib/spack/llnl/util/lock.py
+++ b/lib/spack/llnl/util/lock.py
@@ -39,13 +39,20 @@ _sleep_time = 1e-5
 
 
 class Lock(object):
-    def __init__(self,file_path):
+    """This is an implementation of a filesystem lock using Python's lockf.
+
+    In Python, `lockf` actually calls `fcntl`, so this should work with any
+    filesystem implementation that supports locking through the fcntl calls.
+    This includes distributed filesystems like Lustre (when flock is enabled)
+    and recent NFS versions.
+
+    """
+    def __init__(self, file_path):
         self._file_path = file_path
         self._fd = None
         self._reads = 0
         self._writes = 0
 
-
     def _lock(self, op, timeout):
         """This takes a lock using POSIX locks (``fnctl.lockf``).
 
@@ -80,7 +87,6 @@ class Lock(object):
 
         raise LockError("Timed out waiting for lock.")
 
-
     def _unlock(self):
         """Releases a lock using POSIX locks (``fcntl.lockf``)
 
@@ -88,11 +94,10 @@ class Lock(object):
         be masquerading as write locks, but this removes either.
 
         """
-        fcntl.lockf(self._fd,fcntl.LOCK_UN)
+        fcntl.lockf(self._fd, fcntl.LOCK_UN)
         os.close(self._fd)
         self._fd = None
 
-
     def acquire_read(self, timeout=_default_timeout):
         """Acquires a recursive, shared lock for reading.
 
@@ -112,7 +117,6 @@ class Lock(object):
             self._reads += 1
             return False
 
-
     def acquire_write(self, timeout=_default_timeout):
         """Acquires a recursive, exclusive lock for writing.
 
@@ -132,7 +136,6 @@ class Lock(object):
             self._writes += 1
             return False
 
-
     def release_read(self):
         """Releases a read lock.
 
@@ -153,7 +156,6 @@ class Lock(object):
             self._reads -= 1
             return False
 
-
     def release_write(self):
         """Releases a write lock.
 
diff --git a/lib/spack/spack/__init__.py b/lib/spack/spack/__init__.py
index a6e21987c8..3d508d0fde 100644
--- a/lib/spack/spack/__init__.py
+++ b/lib/spack/spack/__init__.py
@@ -1,3 +1,4 @@
+# flake8: noqa
 ##############################################################################
 # Copyright (c) 2013-2016, Lawrence Livermore National Security, LLC.
 # Produced at the Lawrence Livermore National Laboratory.
@@ -147,7 +148,7 @@ _tmp_user = getpass.getuser()
 _tmp_candidates = (_default_tmp, '/nfs/tmp2', '/tmp', '/var/tmp')
 for path in _tmp_candidates:
     # don't add a second username if it's already unique by user.
-    if not _tmp_user in path:
+    if _tmp_user not in path:
         tmp_dirs.append(join_path(path, '%u', 'spack-stage'))
     else:
         tmp_dirs.append(join_path(path, 'spack-stage'))
@@ -179,12 +180,13 @@ sys_type = None
 # Spack internal code should call 'import spack' and accesses other
 # variables (spack.repo, paths, etc.) directly.
 #
-# TODO: maybe this should be separated out and should go in build_environment.py?
-# TODO: it's not clear where all the stuff that needs to be included in packages
-#       should live.  This file is overloaded for spack core vs. for packages.
+# TODO: maybe this should be separated out to build_environment.py?
+# TODO: it's not clear where all the stuff that needs to be included in
+#       packages should live.  This file is overloaded for spack core vs.
+#       for packages.
 #
-__all__ = ['Package', 'StagedPackage', 'CMakePackage', \
-    'Version', 'when', 'ver', 'alldeps', 'nolink']
+__all__ = ['Package', 'StagedPackage', 'CMakePackage',
+           'Version', 'when', 'ver', 'alldeps', 'nolink']
 from spack.package import Package, ExtensionConflictError
 from spack.package import StagedPackage, CMakePackage
 from spack.version import Version, ver
@@ -204,8 +206,8 @@ from spack.util.executable import *
 __all__ += spack.util.executable.__all__
 
 from spack.package import \
-    install_dependency_symlinks, flatten_dependencies, DependencyConflictError, \
-    InstallError, ExternalPackageError
+    install_dependency_symlinks, flatten_dependencies, \
+    DependencyConflictError, InstallError, ExternalPackageError
 __all__ += [
-    'install_dependency_symlinks', 'flatten_dependencies', 'DependencyConflictError',
-    'InstallError', 'ExternalPackageError']
+    'install_dependency_symlinks', 'flatten_dependencies',
+    'DependencyConflictError', 'InstallError', 'ExternalPackageError']
diff --git a/lib/spack/spack/cmd/purge.py b/lib/spack/spack/cmd/purge.py
index 26745810a8..26d160635c 100644
--- a/lib/spack/spack/cmd/purge.py
+++ b/lib/spack/spack/cmd/purge.py
@@ -45,14 +45,14 @@ def setup_parser(subparser):
 
 def purge(parser, args):
     # Special case: no flags.
-    if not any((args.stage, args.cache, args.all)):
+    if not any((args.stage, args.downloads, args.user_cache, args.all)):
         stage.purge()
         return
 
     # handle other flags with fall through.
     if args.stage or args.all:
         stage.purge()
-    if args.cache or args.all:
+    if args.downloads or args.all:
         spack.fetch_cache.destroy()
     if args.user_cache or args.all:
         spack.user_cache.destroy()
diff --git a/lib/spack/spack/cmd/test.py b/lib/spack/spack/cmd/test.py
index 2667b42820..b9f2a449ae 100644
--- a/lib/spack/spack/cmd/test.py
+++ b/lib/spack/spack/cmd/test.py
@@ -23,23 +23,23 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
 import os
-from pprint import pprint
 
 from llnl.util.filesystem import join_path, mkdirp
 from llnl.util.tty.colify import colify
-from llnl.util.lang import list_modules
 
 import spack
 import spack.test
 from spack.fetch_strategy import FetchError
 
-description ="Run unit tests"
+description = "Run unit tests"
+
 
 def setup_parser(subparser):
     subparser.add_argument(
         'names', nargs='*', help="Names of tests to run.")
     subparser.add_argument(
-        '-l', '--list', action='store_true', dest='list', help="Show available tests")
+        '-l', '--list', action='store_true', dest='list',
+        help="Show available tests")
     subparser.add_argument(
         '--createXmlOutput', action='store_true', dest='createXmlOutput',
         help="Create JUnit XML from test results")
@@ -69,6 +69,7 @@ class MockCacheFetcher(object):
     def __str__(self):
         return "[mock fetcher]"
 
+
 def test(parser, args):
     if args.list:
         print "Available tests:"
diff --git a/lib/spack/spack/database.py b/lib/spack/spack/database.py
index 5ce42b2e67..16814429dc 100644
--- a/lib/spack/spack/database.py
+++ b/lib/spack/spack/database.py
@@ -357,9 +357,9 @@ class Database(object):
 
         This is a helper function called by the WriteTransaction context
         manager. If there is an exception while the write lock is active,
-        nothing will be written to the database file, but the in-memory database
-        *may* be left in an inconsistent state.  It will be consistent after the
-        start of the next transaction, when it read from disk again.
+        nothing will be written to the database file, but the in-memory
+        database *may* be left in an inconsistent state.  It will be consistent
+        after the start of the next transaction, when it read from disk again.
 
         This routine does no locking.
 
diff --git a/lib/spack/spack/file_cache.py b/lib/spack/spack/file_cache.py
index 2124df9c9c..fb9ccf46b8 100644
--- a/lib/spack/spack/file_cache.py
+++ b/lib/spack/spack/file_cache.py
@@ -28,7 +28,6 @@ import shutil
 from llnl.util.filesystem import *
 from llnl.util.lock import *
 
-import spack
 from spack.error import SpackError
 
 
@@ -54,11 +53,14 @@ class FileCache(object):
 
         self._locks = {}
 
-    def purge(self):
+    def destroy(self):
         """Remove all files under the cache root."""
         for f in os.listdir(self.root):
             path = join_path(self.root, f)
-            shutil.rmtree(f)
+            if os.path.isdir(path):
+                shutil.rmtree(path, True)
+            else:
+                os.remove(path)
 
     def cache_path(self, key):
         """Path to the file in the cache for a particular key."""
@@ -92,7 +94,7 @@ class FileCache(object):
             if not os.path.isfile(cache_path):
                 raise CacheError("Cache file is not a file: %s" % cache_path)
 
-            if not os.access(cache_path, os.R_OK|os.W_OK):
+            if not os.access(cache_path, os.R_OK | os.W_OK):
                 raise CacheError("Cannot access cache file: %s" % cache_path)
         else:
             # if the file is hierarchical, make parent directories
@@ -100,7 +102,7 @@ class FileCache(object):
             if parent.rstrip(os.path.sep) != self.root:
                 mkdirp(parent)
 
-            if not os.access(parent, os.R_OK|os.W_OK):
+            if not os.access(parent, os.R_OK | os.W_OK):
                 raise CacheError("Cannot access cache directory: %s" % parent)
 
             # ensure lock is created for this key
@@ -154,7 +156,6 @@ class FileCache(object):
 
         return WriteTransaction(self._get_lock(key), WriteContextManager)
 
-
     def mtime(self, key):
         """Return modification time of cache file, or 0 if it does not exist.
 
@@ -168,7 +169,6 @@ class FileCache(object):
             sinfo = os.stat(self.cache_path(key))
             return sinfo.st_mtime
 
-
     def remove(self, key):
         lock = self._get_lock(key)
         try:
@@ -178,4 +178,6 @@ class FileCache(object):
             lock.release_write()
         os.unlink(self._lock_path(key))
 
-class CacheError(SpackError): pass
+
+class CacheError(SpackError):
+    pass
diff --git a/lib/spack/spack/package.py b/lib/spack/spack/package.py
index 475155937c..25e07541d0 100644
--- a/lib/spack/spack/package.py
+++ b/lib/spack/spack/package.py
@@ -1416,6 +1416,7 @@ def use_cray_compiler_names():
     os.environ['FC'] = 'ftn'
     os.environ['F77'] = 'ftn'
 
+
 def flatten_dependencies(spec, flat_dir):
     """Make each dependency of spec present in dir via symlink."""
     for dep in spec.traverse(root=False):
diff --git a/lib/spack/spack/provider_index.py b/lib/spack/spack/provider_index.py
index ecdc25c4d2..b5fbb67c6e 100644
--- a/lib/spack/spack/provider_index.py
+++ b/lib/spack/spack/provider_index.py
@@ -25,7 +25,7 @@
 """
 The ``virtual`` module contains utility classes for virtual dependencies.
 """
-import itertools
+from itertools import product as iproduct
 from pprint import pformat
 
 import yaml
@@ -52,8 +52,6 @@ class ProviderIndex(object):
        matching implementation of MPI.
 
     """
-
-
     def __init__(self, specs=None, restrict=False):
         """Create a new ProviderIndex.
 
@@ -71,7 +69,8 @@ class ProviderIndex(object):
             as possible without overly restricting results, so it is
             not the best name.
         """
-        if specs is None: specs = []
+        if specs is None:
+            specs = []
 
         self.restrict = restrict
         self.providers = {}
@@ -85,7 +84,6 @@ class ProviderIndex(object):
 
             self.update(spec)
 
-
     def update(self, spec):
         if not isinstance(spec, spack.spec.Spec):
             spec = spack.spec.Spec(spec)
@@ -104,7 +102,7 @@ class ProviderIndex(object):
                 provided_name = provided_spec.name
 
                 provider_map = self.providers.setdefault(provided_name, {})
-                if not provided_spec in provider_map:
+                if provided_spec not in provider_map:
                     provider_map[provided_spec] = set()
 
                 if self.restrict:
@@ -126,7 +124,6 @@ class ProviderIndex(object):
                     constrained.constrain(provider_spec)
                     provider_map[provided_spec].add(constrained)
 
-
     def providers_for(self, *vpkg_specs):
         """Gives specs of all packages that provide virtual packages
            with the supplied specs."""
@@ -138,26 +135,25 @@ class ProviderIndex(object):
 
             # Add all the providers that satisfy the vpkg spec.
             if vspec.name in self.providers:
-                for provider_spec, spec_set in self.providers[vspec.name].items():
-                    if provider_spec.satisfies(vspec, deps=False):
+                for p_spec, spec_set in self.providers[vspec.name].items():
+                    if p_spec.satisfies(vspec, deps=False):
                         providers.update(spec_set)
 
         # Return providers in order
         return sorted(providers)
 
-
     # TODO: this is pretty darned nasty, and inefficient, but there
     # are not that many vdeps in most specs.
     def _cross_provider_maps(self, lmap, rmap):
         result = {}
-        for lspec, rspec in itertools.product(lmap, rmap):
+        for lspec, rspec in iproduct(lmap, rmap):
             try:
                 constrained = lspec.constrained(rspec)
             except spack.spec.UnsatisfiableSpecError:
                 continue
 
             # lp and rp are left and right provider specs.
-            for lp_spec, rp_spec in itertools.product(lmap[lspec], rmap[rspec]):
+            for lp_spec, rp_spec in iproduct(lmap[lspec], rmap[rspec]):
                 if lp_spec.name == rp_spec.name:
                     try:
                         const = lp_spec.constrained(rp_spec, deps=False)
@@ -166,12 +162,10 @@ class ProviderIndex(object):
                         continue
         return result
 
-
     def __contains__(self, name):
         """Whether a particular vpkg name is in the index."""
         return name in self.providers
 
-
     def satisfies(self, other):
         """Check that providers of virtual specs are compatible."""
         common = set(self.providers) & set(other.providers)
@@ -189,7 +183,6 @@ class ProviderIndex(object):
 
         return all(c in result for c in common)
 
-
     def to_yaml(self, stream=None):
         provider_list = self._transform(
             lambda vpkg, pset: [
@@ -198,7 +191,6 @@ class ProviderIndex(object):
         yaml.dump({'provider_index': {'providers': provider_list}},
                   stream=stream)
 
-
     @staticmethod
     def from_yaml(stream):
         try:
@@ -211,7 +203,7 @@ class ProviderIndex(object):
             raise spack.spec.SpackYAMLError(
                 "YAML ProviderIndex was not a dict.")
 
-        if not 'provider_index' in yfile:
+        if 'provider_index' not in yfile:
             raise spack.spec.SpackYAMLError(
                 "YAML ProviderIndex does not start with 'provider_index'")
 
@@ -224,7 +216,6 @@ class ProviderIndex(object):
                 set(spack.spec.Spec.from_node_dict(p) for p in plist)))
         return index
 
-
     def merge(self, other):
         """Merge `other` ProviderIndex into this one."""
         other = other.copy()   # defensive copy.
@@ -242,7 +233,6 @@ class ProviderIndex(object):
 
                 spdict[provided_spec] += opdict[provided_spec]
 
-
     def remove_provider(self, pkg_name):
         """Remove a provider from the ProviderIndex."""
         empty_pkg_dict = []
@@ -264,7 +254,6 @@ class ProviderIndex(object):
         for pkg in empty_pkg_dict:
             del self.providers[pkg]
 
-
     def copy(self):
         """Deep copy of this ProviderIndex."""
         clone = ProviderIndex()
@@ -272,15 +261,12 @@ class ProviderIndex(object):
             lambda vpkg, pset: (vpkg, set((p.copy() for p in pset))))
         return clone
 
-
     def __eq__(self, other):
         return self.providers == other.providers
 
-
     def _transform(self, transform_fun, out_mapping_type=dict):
         return _transform(self.providers, transform_fun, out_mapping_type)
 
-
     def __str__(self):
         return pformat(
             _transform(self.providers,
diff --git a/lib/spack/spack/repository.py b/lib/spack/spack/repository.py
index a0904a2cde..eada10f7cb 100644
--- a/lib/spack/spack/repository.py
+++ b/lib/spack/spack/repository.py
@@ -38,7 +38,6 @@ from types import ModuleType
 import yaml
 
 import llnl.util.tty as tty
-from llnl.util.lock import Lock
 from llnl.util.filesystem import *
 
 import spack
@@ -142,7 +141,6 @@ class RepoPath(object):
                          "To remove the bad repository, run this command:",
                          "    spack repo rm %s" % root)
 
-
     def swap(self, other):
         """Convenience function to make swapping repostiories easier.
 
@@ -160,7 +158,6 @@ class RepoPath(object):
             setattr(self, attr, getattr(other, attr))
             setattr(other, attr, tmp)
 
-
     def _add(self, repo):
         """Add a repository to the namespace and path indexes.
 
@@ -174,31 +171,28 @@ class RepoPath(object):
         if repo.namespace in self.by_namespace:
             raise DuplicateRepoError(
                 "Package repos '%s' and '%s' both provide namespace %s"
-                % (repo.root, self.by_namespace[repo.namespace].root, repo.namespace))
+                % (repo.root, self.by_namespace[repo.namespace].root,
+                   repo.namespace))
 
         # Add repo to the pkg indexes
         self.by_namespace[repo.full_namespace] = repo
         self.by_path[repo.root] = repo
 
-
     def put_first(self, repo):
         """Add repo first in the search path."""
         self._add(repo)
         self.repos.insert(0, repo)
 
-
     def put_last(self, repo):
         """Add repo last in the search path."""
         self._add(repo)
         self.repos.append(repo)
 
-
     def remove(self, repo):
         """Remove a repo from the search path."""
         if repo in self.repos:
             self.repos.remove(repo)
 
-
     def get_repo(self, namespace, default=NOT_PROVIDED):
         """Get a repository by namespace.
         Arguments
@@ -218,12 +212,10 @@ class RepoPath(object):
             return default
         return self.by_namespace[fullspace]
 
-
     def first_repo(self):
         """Get the first repo in precedence order."""
         return self.repos[0] if self.repos else None
 
-
     def all_package_names(self):
         """Return all unique package names in all repositories."""
         if self._all_package_names is None:
@@ -231,15 +223,13 @@ class RepoPath(object):
             for repo in self.repos:
                 for name in repo.all_package_names():
                     all_pkgs.add(name)
-            self._all_package_names = sorted(all_pkgs, key=lambda n:n.lower())
+            self._all_package_names = sorted(all_pkgs, key=lambda n: n.lower())
         return self._all_package_names
 
-
     def all_packages(self):
         for name in self.all_package_names():
             yield self.get(name)
 
-
     @property
     def provider_index(self):
         """Merged ProviderIndex from all Repos in the RepoPath."""
@@ -250,7 +240,6 @@ class RepoPath(object):
 
         return self._provider_index
 
-
     @_autospec
     def providers_for(self, vpkg_spec):
         providers = self.provider_index.providers_for(vpkg_spec)
@@ -258,12 +247,10 @@ class RepoPath(object):
             raise UnknownPackageError(vpkg_spec.name)
         return providers
 
-
     @_autospec
     def extensions_for(self, extendee_spec):
         return [p for p in self.all_packages() if p.extends(extendee_spec)]
 
-
     def find_module(self, fullname, path=None):
         """Implements precedence for overlaid namespaces.
 
@@ -290,7 +277,6 @@ class RepoPath(object):
 
         return None
 
-
     def load_module(self, fullname):
         """Handles loading container namespaces when necessary.
 
@@ -307,7 +293,6 @@ class RepoPath(object):
         sys.modules[fullname] = module
         return module
 
-
     @_autospec
     def repo_for_pkg(self, spec):
         """Given a spec, get the repository for its package."""
@@ -329,7 +314,6 @@ class RepoPath(object):
         # that can operate on packages that don't exist yet.
         return self.first_repo()
 
-
     @_autospec
     def get(self, spec, new=False):
         """Find a repo that contains the supplied spec's package.
@@ -338,12 +322,10 @@ class RepoPath(object):
         """
         return self.repo_for_pkg(spec).get(spec)
 
-
     def get_pkg_class(self, pkg_name):
         """Find a class for the spec's package and return the class object."""
         return self.repo_for_pkg(pkg_name).get_pkg_class(pkg_name)
 
-
     @_autospec
     def dump_provenance(self, spec, path):
         """Dump provenance information for a spec to a particular path.
@@ -353,24 +335,19 @@ class RepoPath(object):
         """
         return self.repo_for_pkg(spec).dump_provenance(spec, path)
 
-
     def dirname_for_package_name(self, pkg_name):
         return self.repo_for_pkg(pkg_name).dirname_for_package_name(pkg_name)
 
-
     def filename_for_package_name(self, pkg_name):
         return self.repo_for_pkg(pkg_name).filename_for_package_name(pkg_name)
 
-
     def exists(self, pkg_name):
         return any(repo.exists(pkg_name) for repo in self.repos)
 
-
     def __contains__(self, pkg_name):
         return self.exists(pkg_name)
 
 
-
 class Repo(object):
     """Class representing a package repository in the filesystem.
 
@@ -404,7 +381,8 @@ class Repo(object):
 
         # check and raise BadRepoError on fail.
         def check(condition, msg):
-            if not condition: raise BadRepoError(msg)
+            if not condition:
+                raise BadRepoError(msg)
 
         # Validate repository layout.
         self.config_file = join_path(self.root, repo_config_name)
@@ -422,12 +400,14 @@ class Repo(object):
 
         self.namespace = config['namespace']
         check(re.match(r'[a-zA-Z][a-zA-Z0-9_.]+', self.namespace),
-              ("Invalid namespace '%s' in repo '%s'. "  % (self.namespace, self.root)) +
+              ("Invalid namespace '%s' in repo '%s'. "
+               % (self.namespace, self.root)) +
               "Namespaces must be valid python identifiers separated by '.'")
 
         # Set up 'full_namespace' to include the super-namespace
         if self.super_namespace:
-            self.full_namespace = "%s.%s" % (self.super_namespace, self.namespace)
+            self.full_namespace = "%s.%s" % (
+                self.super_namespace, self.namespace)
         else:
             self.full_namespace = self.namespace
 
@@ -462,10 +442,10 @@ class Repo(object):
 
         """
         parent = None
-        for l in range(1, len(self._names)+1):
+        for l in range(1, len(self._names) + 1):
             ns = '.'.join(self._names[:l])
 
-            if not ns in sys.modules:
+            if ns not in sys.modules:
                 module = SpackNamespace(ns)
                 module.__loader__ = self
                 sys.modules[ns] = module
@@ -476,7 +456,7 @@ class Repo(object):
                 # This ensures that we can do things like:
                 #    import spack.pkg.builtin.mpich as mpich
                 if parent:
-                    modname = self._names[l-1]
+                    modname = self._names[l - 1]
                     setattr(parent, modname, module)
             else:
                 # no need to set up a module
@@ -485,7 +465,6 @@ class Repo(object):
             # but keep track of the parent in this loop
             parent = module
 
-
     def real_name(self, import_name):
         """Allow users to import Spack packages using Python identifiers.
 
@@ -511,13 +490,11 @@ class Repo(object):
                 return name
         return None
 
-
     def is_prefix(self, fullname):
         """True if fullname is a prefix of this Repo's namespace."""
         parts = fullname.split('.')
         return self._names[:len(parts)] == parts
 
-
     def find_module(self, fullname, path=None):
         """Python find_module import hook.
 
@@ -533,7 +510,6 @@ class Repo(object):
 
         return None
 
-
     def load_module(self, fullname):
         """Python importer load hook.
 
@@ -565,7 +541,6 @@ class Repo(object):
 
         return module
 
-
     def _read_config(self):
         """Check for a YAML config file in this db's root directory."""
         try:
@@ -573,40 +548,39 @@ class Repo(object):
                 yaml_data = yaml.load(reponame_file)
 
                 if (not yaml_data or 'repo' not in yaml_data or
-                    not isinstance(yaml_data['repo'], dict)):
-                    tty.die("Invalid %s in repository %s"
-                            % (repo_config_name, self.root))
+                        not isinstance(yaml_data['repo'], dict)):
+                    tty.die("Invalid %s in repository %s" % (
+                        repo_config_name, self.root))
 
                 return yaml_data['repo']
 
-        except exceptions.IOError, e:
+        except exceptions.IOError:
             tty.die("Error reading %s when opening %s"
                     % (self.config_file, self.root))
 
-
     @_autospec
     def get(self, spec, new=False):
         if spec.virtual:
             raise UnknownPackageError(spec.name)
 
         if spec.namespace and spec.namespace != self.namespace:
-            raise UnknownPackageError("Repository %s does not contain package %s"
-                                      % (self.namespace, spec.fullname))
+            raise UnknownPackageError(
+                "Repository %s does not contain package %s"
+                % (self.namespace, spec.fullname))
 
         key = hash(spec)
         if new or key not in self._instances:
             package_class = self.get_pkg_class(spec.name)
             try:
-                copy = spec.copy() # defensive copy.  Package owns its spec.
+                copy = spec.copy()  # defensive copy.  Package owns its spec.
                 self._instances[key] = package_class(copy)
-            except Exception, e:
+            except Exception:
                 if spack.debug:
                     sys.excepthook(*sys.exc_info())
                 raise FailedConstructorError(spec.fullname, *sys.exc_info())
 
         return self._instances[key]
 
-
     @_autospec
     def dump_provenance(self, spec, path):
         """Dump provenance information for a spec to a particular path.
@@ -619,8 +593,9 @@ class Repo(object):
             raise UnknownPackageError(spec.name)
 
         if spec.namespace and spec.namespace != self.namespace:
-            raise UnknownPackageError("Repository %s does not contain package %s."
-                                      % (self.namespace, spec.fullname))
+            raise UnknownPackageError(
+                "Repository %s does not contain package %s."
+                % (self.namespace, spec.fullname))
 
         # Install any patch files needed by packages.
         mkdirp(path)
@@ -635,12 +610,10 @@ class Repo(object):
         # Install the package.py file itself.
         install(self.filename_for_package_name(spec), path)
 
-
     def purge(self):
         """Clear entire package instance cache."""
         self._instances.clear()
 
-
     def _update_provider_index(self):
         # Check modification dates of all packages
         self._fast_package_check()
@@ -669,7 +642,6 @@ class Repo(object):
 
                 self._provider_index.to_yaml(new)
 
-
     @property
     def provider_index(self):
         """A provider index with names *specific* to this repo."""
@@ -677,7 +649,6 @@ class Repo(object):
             self._update_provider_index()
         return self._provider_index
 
-
     @_autospec
     def providers_for(self, vpkg_spec):
         providers = self.provider_index.providers_for(vpkg_spec)
@@ -685,18 +656,15 @@ class Repo(object):
             raise UnknownPackageError(vpkg_spec.name)
         return providers
 
-
     @_autospec
     def extensions_for(self, extendee_spec):
         return [p for p in self.all_packages() if p.extends(extendee_spec)]
 
-
     def _check_namespace(self, spec):
         """Check that the spec's namespace is the same as this repository's."""
         if spec.namespace and spec.namespace != self.namespace:
             raise UnknownNamespaceError(spec.namespace)
 
-
     @_autospec
     def dirname_for_package_name(self, spec):
         """Get the directory name for a particular package.  This is the
@@ -704,7 +672,6 @@ class Repo(object):
         self._check_namespace(spec)
         return join_path(self.packages_path, spec.name)
 
-
     @_autospec
     def filename_for_package_name(self, spec):
         """Get the filename for the module we should load for a particular
@@ -719,7 +686,6 @@ class Repo(object):
         pkg_dir = self.dirname_for_package_name(spec.name)
         return join_path(pkg_dir, package_file_name)
 
-
     def _fast_package_check(self):
         """List packages in the repo and check whether index is up to date.
 
@@ -783,13 +749,11 @@ class Repo(object):
 
         return self._all_package_names
 
-
     def all_package_names(self):
         """Returns a sorted list of all package names in the Repo."""
         self._fast_package_check()
         return self._all_package_names
 
-
     def all_packages(self):
         """Iterator over all packages in the repository.
 
@@ -799,7 +763,6 @@ class Repo(object):
         for name in self.all_package_names():
             yield self.get(name)
 
-
     def exists(self, pkg_name):
         """Whether a package with the supplied name exists."""
         if self._all_package_names:
@@ -813,7 +776,6 @@ class Repo(object):
         filename = self.filename_for_package_name(pkg_name)
         return os.path.exists(filename)
 
-
     def _get_pkg_module(self, pkg_name):
         """Create a module for a particular package.
 
@@ -845,7 +807,6 @@ class Repo(object):
 
         return self._modules[pkg_name]
 
-
     def get_pkg_class(self, pkg_name):
         """Get the class for the package out of its module.
 
@@ -853,7 +814,6 @@ class Repo(object):
         package. Then extracts the package class from the module
         according to Spack's naming convention.
         """
-        fullname = pkg_name
         namespace, _, pkg_name = pkg_name.rpartition('.')
         if namespace and (namespace != self.namespace):
             raise InvalidNamespaceError('Invalid namespace for %s repo: %s'
@@ -868,15 +828,12 @@ class Repo(object):
 
         return cls
 
-
     def __str__(self):
         return "[Repo '%s' at '%s']" % (self.namespace, self.root)
 
-
     def __repr__(self):
         return self.__str__()
 
-
     def __contains__(self, pkg_name):
         return self.exists(pkg_name)
 
@@ -885,30 +842,37 @@ def create_repo(root, namespace=None):
     """Create a new repository in root with the specified namespace.
 
        If the namespace is not provided, use basename of root.
-       Return the canonicalized path and the namespace of the created repository.
+       Return the canonicalized path and namespace of the created repository.
     """
     root = canonicalize_path(root)
     if not namespace:
         namespace = os.path.basename(root)
 
     if not re.match(r'\w[\.\w-]*', namespace):
-        raise InvalidNamespaceError("'%s' is not a valid namespace." % namespace)
+        raise InvalidNamespaceError(
+            "'%s' is not a valid namespace." % namespace)
 
     existed = False
     if os.path.exists(root):
         if os.path.isfile(root):
-            raise BadRepoError('File %s already exists and is not a directory' % root)
+            raise BadRepoError('File %s already exists and is not a directory'
+                               % root)
         elif os.path.isdir(root):
             if not os.access(root, os.R_OK | os.W_OK):
-                raise BadRepoError('Cannot create new repo in %s: cannot access directory.' % root)
+                raise BadRepoError(
+                    'Cannot create new repo in %s: cannot access directory.'
+                    % root)
             if os.listdir(root):
-                raise BadRepoError('Cannot create new repo in %s: directory is not empty.' % root)
+                raise BadRepoError(
+                    'Cannot create new repo in %s: directory is not empty.'
+                    % root)
         existed = True
 
     full_path = os.path.realpath(root)
     parent = os.path.dirname(full_path)
     if not os.access(parent, os.R_OK | os.W_OK):
-        raise BadRepoError("Cannot create repository in %s: can't access parent!" % root)
+        raise BadRepoError(
+            "Cannot create repository in %s: can't access parent!" % root)
 
     try:
         config_path = os.path.join(root, repo_config_name)
diff --git a/lib/spack/spack/test/__init__.py b/lib/spack/spack/test/__init__.py
index 4969081e63..db683917b5 100644
--- a/lib/spack/spack/test/__init__.py
+++ b/lib/spack/spack/test/__init__.py
@@ -82,6 +82,7 @@ test_names = [
     'cmd.test_compiler_cmd',
 ]
 
+
 def list_tests():
     """Return names of all tests that can be run for Spack."""
     return test_names
diff --git a/lib/spack/spack/test/concretize.py b/lib/spack/spack/test/concretize.py
index ec0a2ec244..8ecbddbda2 100644
--- a/lib/spack/spack/test/concretize.py
+++ b/lib/spack/spack/test/concretize.py
@@ -29,6 +29,7 @@ from spack.version import ver
 from spack.concretize import find_spec
 from spack.test.mock_packages_test import *
 
+
 class ConcretizeTest(MockPackagesTest):
 
     def check_spec(self, abstract, concrete):
@@ -59,7 +60,6 @@ class ConcretizeTest(MockPackagesTest):
         if abstract.architecture and abstract.architecture.concrete:
             self.assertEqual(abstract.architecture, concrete.architecture)
 
-
     def check_concretize(self, abstract_spec):
         abstract = Spec(abstract_spec)
         concrete = abstract.concretized()
@@ -70,29 +70,24 @@ class ConcretizeTest(MockPackagesTest):
 
         return concrete
 
-
     def test_concretize_no_deps(self):
         self.check_concretize('libelf')
         self.check_concretize('libelf@0.8.13')
 
-
     def test_concretize_dag(self):
         self.check_concretize('callpath')
         self.check_concretize('mpileaks')
         self.check_concretize('libelf')
 
-
     def test_concretize_variant(self):
         self.check_concretize('mpich+debug')
         self.check_concretize('mpich~debug')
         self.check_concretize('mpich debug=2')
         self.check_concretize('mpich')
 
-
     def test_conretize_compiler_flags(self):
         self.check_concretize('mpich cppflags="-O3"')
 
-
     def test_concretize_preferred_version(self):
         spec = self.check_concretize('python')
         self.assertEqual(spec.versions, ver('2.7.11'))
@@ -100,7 +95,6 @@ class ConcretizeTest(MockPackagesTest):
         spec = self.check_concretize('python@3.5.1')
         self.assertEqual(spec.versions, ver('3.5.1'))
 
-
     def test_concretize_with_virtual(self):
         self.check_concretize('mpileaks ^mpi')
         self.check_concretize('mpileaks ^mpi@:1.1')
@@ -111,7 +105,6 @@ class ConcretizeTest(MockPackagesTest):
         self.check_concretize('mpileaks ^mpi@:1')
         self.check_concretize('mpileaks ^mpi@1.2:2')
 
-
     def test_concretize_with_restricted_virtual(self):
         self.check_concretize('mpileaks ^mpich2')
 
@@ -142,55 +135,55 @@ class ConcretizeTest(MockPackagesTest):
         concrete = self.check_concretize('mpileaks   ^mpich2@1.3.1:1.4')
         self.assertTrue(concrete['mpich2'].satisfies('mpich2@1.3.1:1.4'))
 
-
     def test_concretize_with_provides_when(self):
         """Make sure insufficient versions of MPI are not in providers list when
            we ask for some advanced version.
         """
-        self.assertTrue(not any(spec.satisfies('mpich2@:1.0')
-                                for spec in spack.repo.providers_for('mpi@2.1')))
+        self.assertTrue(
+            not any(spec.satisfies('mpich2@:1.0')
+                    for spec in spack.repo.providers_for('mpi@2.1')))
 
-        self.assertTrue(not any(spec.satisfies('mpich2@:1.1')
-                                for spec in spack.repo.providers_for('mpi@2.2')))
+        self.assertTrue(
+            not any(spec.satisfies('mpich2@:1.1')
+                    for spec in spack.repo.providers_for('mpi@2.2')))
 
-        self.assertTrue(not any(spec.satisfies('mpich@:1')
-                                for spec in spack.repo.providers_for('mpi@2')))
+        self.assertTrue(
+            not any(spec.satisfies('mpich@:1')
+                    for spec in spack.repo.providers_for('mpi@2')))
 
-        self.assertTrue(not any(spec.satisfies('mpich@:1')
-                                for spec in spack.repo.providers_for('mpi@3')))
-
-        self.assertTrue(not any(spec.satisfies('mpich2')
-                                for spec in spack.repo.providers_for('mpi@3')))
+        self.assertTrue(
+            not any(spec.satisfies('mpich@:1')
+                    for spec in spack.repo.providers_for('mpi@3')))
 
+        self.assertTrue(
+            not any(spec.satisfies('mpich2')
+                    for spec in spack.repo.providers_for('mpi@3')))
 
     def test_concretize_two_virtuals(self):
         """Test a package with multiple virtual dependencies."""
-        s = Spec('hypre').concretize()
-
+        Spec('hypre').concretize()
 
     def test_concretize_two_virtuals_with_one_bound(self):
         """Test a package with multiple virtual dependencies and one preset."""
-        s = Spec('hypre ^openblas').concretize()
-
+        Spec('hypre ^openblas').concretize()
 
     def test_concretize_two_virtuals_with_two_bound(self):
-        """Test a package with multiple virtual dependencies and two of them preset."""
-        s = Spec('hypre ^openblas ^netlib-lapack').concretize()
-
+        """Test a package with multiple virtual deps and two of them preset."""
+        Spec('hypre ^openblas ^netlib-lapack').concretize()
 
     def test_concretize_two_virtuals_with_dual_provider(self):
         """Test a package with multiple virtual dependencies and force a provider
            that provides both."""
-        s = Spec('hypre ^openblas-with-lapack').concretize()
-
+        Spec('hypre ^openblas-with-lapack').concretize()
 
     def test_concretize_two_virtuals_with_dual_provider_and_a_conflict(self):
-        """Test a package with multiple virtual dependencies and force a provider
-           that provides both, and another conflicting package that provides one."""
+        """Test a package with multiple virtual dependencies and force a
+           provider that provides both, and another conflicting package that
+           provides one.
+        """
         s = Spec('hypre ^openblas-with-lapack ^netlib-lapack')
         self.assertRaises(spack.spec.MultipleProviderError, s.concretize)
 
-
     def test_virtual_is_fully_expanded_for_callpath(self):
         # force dependence on fake "zmpi" by asking for MPI 10.0
         spec = Spec('callpath ^mpi@10.0')
@@ -207,7 +200,6 @@ class ConcretizeTest(MockPackagesTest):
 
         self.assertTrue('fake' in spec._dependencies['zmpi'].spec)
 
-
     def test_virtual_is_fully_expanded_for_mpileaks(self):
         spec = Spec('mpileaks ^mpi@10.0')
         self.assertTrue('mpi' in spec._dependencies)
@@ -217,23 +209,24 @@ class ConcretizeTest(MockPackagesTest):
 
         self.assertTrue('zmpi' in spec._dependencies)
         self.assertTrue('callpath' in spec._dependencies)
-        self.assertTrue('zmpi' in spec._dependencies['callpath'].
-                                  spec._dependencies)
-        self.assertTrue('fake' in spec._dependencies['callpath'].
-                                  spec._dependencies['zmpi'].
-                                  spec._dependencies)
-
-        self.assertTrue(all(not 'mpi' in d._dependencies for d in spec.traverse()))
+        self.assertTrue(
+            'zmpi' in spec._dependencies['callpath']
+            .spec._dependencies)
+        self.assertTrue(
+            'fake' in spec._dependencies['callpath']
+            .spec._dependencies['zmpi']
+            .spec._dependencies)
+
+        self.assertTrue(
+            all('mpi' not in d._dependencies for d in spec.traverse()))
         self.assertTrue('zmpi' in spec)
         self.assertTrue('mpi' in spec)
 
-
     def test_my_dep_depends_on_provider_of_my_virtual_dep(self):
         spec = Spec('indirect_mpich')
         spec.normalize()
         spec.concretize()
 
-
     def test_compiler_inheritance(self):
         spec = Spec('mpileaks')
         spec.normalize()
@@ -245,26 +238,26 @@ class ConcretizeTest(MockPackagesTest):
         self.assertTrue(spec['libdwarf'].compiler.satisfies('clang'))
         self.assertTrue(spec['libelf'].compiler.satisfies('clang'))
 
-
     def test_external_package(self):
         spec = Spec('externaltool%gcc')
         spec.concretize()
 
-        self.assertEqual(spec['externaltool'].external, '/path/to/external_tool')
+        self.assertEqual(
+            spec['externaltool'].external, '/path/to/external_tool')
         self.assertFalse('externalprereq' in spec)
         self.assertTrue(spec['externaltool'].compiler.satisfies('gcc'))
 
-
     def test_external_package_module(self):
         # No tcl modules on darwin/linux machines
         # TODO: improved way to check for this.
-        if (spack.architecture.platform().name == 'darwin' or
-            spack.architecture.platform().name == 'linux'):
+        platform = spack.architecture.platform().name
+        if (platform == 'darwin' or platform == 'linux'):
             return
 
         spec = Spec('externalmodule')
         spec.concretize()
-        self.assertEqual(spec['externalmodule'].external_module, 'external-module')
+        self.assertEqual(
+            spec['externalmodule'].external_module, 'external-module')
         self.assertFalse('externalprereq' in spec)
         self.assertTrue(spec['externalmodule'].compiler.satisfies('gcc'))
 
@@ -277,16 +270,16 @@ class ConcretizeTest(MockPackagesTest):
             got_error = True
         self.assertTrue(got_error)
 
-
     def test_external_and_virtual(self):
         spec = Spec('externaltest')
         spec.concretize()
-        self.assertEqual(spec['externaltool'].external, '/path/to/external_tool')
-        self.assertEqual(spec['stuff'].external, '/path/to/external_virtual_gcc')
+        self.assertEqual(
+            spec['externaltool'].external, '/path/to/external_tool')
+        self.assertEqual(
+            spec['stuff'].external, '/path/to/external_virtual_gcc')
         self.assertTrue(spec['externaltool'].compiler.satisfies('gcc'))
         self.assertTrue(spec['stuff'].compiler.satisfies('gcc'))
 
-
     def test_find_spec_parents(self):
         """Tests the spec finding logic used by concretization. """
         s = Spec('a +foo',
@@ -297,7 +290,6 @@ class ConcretizeTest(MockPackagesTest):
 
         self.assertEqual('a', find_spec(s['b'], lambda s: '+foo' in s).name)
 
-
     def test_find_spec_children(self):
         s = Spec('a',
                  Spec('b +foo',
@@ -312,7 +304,6 @@ class ConcretizeTest(MockPackagesTest):
                  Spec('e +foo'))
         self.assertEqual('c', find_spec(s['b'], lambda s: '+foo' in s).name)
 
-
     def test_find_spec_sibling(self):
         s = Spec('a',
                  Spec('b +foo',
@@ -330,7 +321,6 @@ class ConcretizeTest(MockPackagesTest):
                       Spec('f +foo')))
         self.assertEqual('f', find_spec(s['b'], lambda s: '+foo' in s).name)
 
-
     def test_find_spec_self(self):
         s = Spec('a',
                  Spec('b +foo',
@@ -339,7 +329,6 @@ class ConcretizeTest(MockPackagesTest):
                  Spec('e'))
         self.assertEqual('b', find_spec(s['b'], lambda s: '+foo' in s).name)
 
-
     def test_find_spec_none(self):
         s = Spec('a',
                  Spec('b',
@@ -348,7 +337,6 @@ class ConcretizeTest(MockPackagesTest):
                  Spec('e'))
         self.assertEqual(None, find_spec(s['b'], lambda s: '+foo' in s))
 
-
     def test_compiler_child(self):
         s = Spec('mpileaks%clang ^dyninst%gcc')
         s.concretize()
diff --git a/lib/spack/spack/test/database.py b/lib/spack/spack/test/database.py
index a2f09450bc..0d44a27b7e 100644
--- a/lib/spack/spack/test/database.py
+++ b/lib/spack/spack/test/database.py
@@ -31,7 +31,6 @@ import multiprocessing
 
 import spack
 from llnl.util.filesystem import join_path
-from llnl.util.lock import *
 from llnl.util.tty.colify import colify
 from spack.test.mock_database import MockDatabase
 
@@ -88,26 +87,28 @@ class DatabaseTest(MockDatabase):
         # query specs with multiple configurations
         mpileaks_specs = [s for s in all_specs if s.satisfies('mpileaks')]
         callpath_specs = [s for s in all_specs if s.satisfies('callpath')]
-        mpi_specs =      [s for s in all_specs if s.satisfies('mpi')]
+        mpi_specs      = [s for s in all_specs if s.satisfies('mpi')]
 
         self.assertEqual(len(mpileaks_specs), 3)
         self.assertEqual(len(callpath_specs), 3)
         self.assertEqual(len(mpi_specs),      3)
 
         # query specs with single configurations
-        dyninst_specs =  [s for s in all_specs if s.satisfies('dyninst')]
+        dyninst_specs  = [s for s in all_specs if s.satisfies('dyninst')]
         libdwarf_specs = [s for s in all_specs if s.satisfies('libdwarf')]
-        libelf_specs =   [s for s in all_specs if s.satisfies('libelf')]
+        libelf_specs   = [s for s in all_specs if s.satisfies('libelf')]
 
         self.assertEqual(len(dyninst_specs),  1)
         self.assertEqual(len(libdwarf_specs), 1)
         self.assertEqual(len(libelf_specs),   1)
 
         # Query by dependency
-        self.assertEqual(len([s for s in all_specs if s.satisfies('mpileaks ^mpich')]),  1)
-        self.assertEqual(len([s for s in all_specs if s.satisfies('mpileaks ^mpich2')]), 1)
-        self.assertEqual(len([s for s in all_specs if s.satisfies('mpileaks ^zmpi')]),   1)
-
+        self.assertEqual(
+            len([s for s in all_specs if s.satisfies('mpileaks ^mpich')]), 1)
+        self.assertEqual(
+            len([s for s in all_specs if s.satisfies('mpileaks ^mpich2')]), 1)
+        self.assertEqual(
+            len([s for s in all_specs if s.satisfies('mpileaks ^zmpi')]), 1)
 
     def test_015_write_and_read(self):
         # write and read DB
@@ -122,7 +123,6 @@ class DatabaseTest(MockDatabase):
             self.assertEqual(new_rec.path,      rec.path)
             self.assertEqual(new_rec.installed, rec.installed)
 
-
     def _check_db_sanity(self):
         """Utiilty function to check db against install layout."""
         expected = sorted(spack.install_layout.all_specs())
@@ -132,12 +132,10 @@ class DatabaseTest(MockDatabase):
         for e, a in zip(expected, actual):
             self.assertEqual(e, a)
 
-
     def test_020_db_sanity(self):
         """Make sure query() returns what's actually in the db."""
         self._check_db_sanity()
 
-
     def test_030_db_sanity_from_another_process(self):
         def read_and_modify():
             self._check_db_sanity()  # check that other process can read DB
@@ -152,30 +150,28 @@ class DatabaseTest(MockDatabase):
         with self.installed_db.read_transaction():
             self.assertEqual(len(self.installed_db.query('mpileaks ^zmpi')), 0)
 
-
     def test_040_ref_counts(self):
         """Ensure that we got ref counts right when we read the DB."""
         self.installed_db._check_ref_counts()
 
-
     def test_050_basic_query(self):
-        """Ensure that querying the database is consistent with what is installed."""
+        """Ensure querying database is consistent with what is installed."""
         # query everything
         self.assertEqual(len(spack.installed_db.query()), 13)
 
         # query specs with multiple configurations
         mpileaks_specs = self.installed_db.query('mpileaks')
         callpath_specs = self.installed_db.query('callpath')
-        mpi_specs =      self.installed_db.query('mpi')
+        mpi_specs      = self.installed_db.query('mpi')
 
         self.assertEqual(len(mpileaks_specs), 3)
         self.assertEqual(len(callpath_specs), 3)
         self.assertEqual(len(mpi_specs),      3)
 
         # query specs with single configurations
-        dyninst_specs =  self.installed_db.query('dyninst')
+        dyninst_specs  = self.installed_db.query('dyninst')
         libdwarf_specs = self.installed_db.query('libdwarf')
-        libelf_specs =   self.installed_db.query('libelf')
+        libelf_specs   = self.installed_db.query('libelf')
 
         self.assertEqual(len(dyninst_specs),  1)
         self.assertEqual(len(libdwarf_specs), 1)
@@ -186,7 +182,6 @@ class DatabaseTest(MockDatabase):
         self.assertEqual(len(self.installed_db.query('mpileaks ^mpich2')), 1)
         self.assertEqual(len(self.installed_db.query('mpileaks ^zmpi')),   1)
 
-
     def _check_remove_and_add_package(self, spec):
         """Remove a spec from the DB, then add it and make sure everything's
            still ok once it is added.  This checks that it was
@@ -215,15 +210,12 @@ class DatabaseTest(MockDatabase):
         self._check_db_sanity()
         self.installed_db._check_ref_counts()
 
-
     def test_060_remove_and_add_root_package(self):
         self._check_remove_and_add_package('mpileaks ^mpich')
 
-
     def test_070_remove_and_add_dependency_package(self):
         self._check_remove_and_add_package('dyninst')
 
-
     def test_080_root_ref_counts(self):
         rec = self.installed_db.get_record('mpileaks ^mpich')
 
@@ -231,44 +223,52 @@ class DatabaseTest(MockDatabase):
         self.installed_db.remove('mpileaks ^mpich')
 
         # record no longer in DB
-        self.assertEqual(self.installed_db.query('mpileaks ^mpich', installed=any), [])
+        self.assertEqual(
+            self.installed_db.query('mpileaks ^mpich', installed=any), [])
 
         # record's deps have updated ref_counts
-        self.assertEqual(self.installed_db.get_record('callpath ^mpich').ref_count, 0)
+        self.assertEqual(
+            self.installed_db.get_record('callpath ^mpich').ref_count, 0)
         self.assertEqual(self.installed_db.get_record('mpich').ref_count, 1)
 
-        # put the spec back
+        # Put the spec back
         self.installed_db.add(rec.spec, rec.path)
 
         # record is present again
-        self.assertEqual(len(self.installed_db.query('mpileaks ^mpich', installed=any)), 1)
+        self.assertEqual(
+            len(self.installed_db.query('mpileaks ^mpich', installed=any)), 1)
 
         # dependencies have ref counts updated
-        self.assertEqual(self.installed_db.get_record('callpath ^mpich').ref_count, 1)
+        self.assertEqual(
+            self.installed_db.get_record('callpath ^mpich').ref_count, 1)
         self.assertEqual(self.installed_db.get_record('mpich').ref_count, 2)
 
-
     def test_090_non_root_ref_counts(self):
-        mpileaks_mpich_rec = self.installed_db.get_record('mpileaks ^mpich')
-        callpath_mpich_rec = self.installed_db.get_record('callpath ^mpich')
+        self.installed_db.get_record('mpileaks ^mpich')
+        self.installed_db.get_record('callpath ^mpich')
 
         # "force remove" a non-root spec from the DB
         self.installed_db.remove('callpath ^mpich')
 
         # record still in DB but marked uninstalled
-        self.assertEqual(self.installed_db.query('callpath ^mpich', installed=True), [])
-        self.assertEqual(len(self.installed_db.query('callpath ^mpich', installed=any)), 1)
+        self.assertEqual(
+            self.installed_db.query('callpath ^mpich', installed=True), [])
+        self.assertEqual(
+            len(self.installed_db.query('callpath ^mpich', installed=any)), 1)
 
         # record and its deps have same ref_counts
-        self.assertEqual(self.installed_db.get_record('callpath ^mpich', installed=any).ref_count, 1)
+        self.assertEqual(self.installed_db.get_record(
+            'callpath ^mpich', installed=any).ref_count, 1)
         self.assertEqual(self.installed_db.get_record('mpich').ref_count, 2)
 
         # remove only dependent of uninstalled callpath record
         self.installed_db.remove('mpileaks ^mpich')
 
         # record and parent are completely gone.
-        self.assertEqual(self.installed_db.query('mpileaks ^mpich', installed=any), [])
-        self.assertEqual(self.installed_db.query('callpath ^mpich', installed=any), [])
+        self.assertEqual(
+            self.installed_db.query('mpileaks ^mpich', installed=any), [])
+        self.assertEqual(
+            self.installed_db.query('callpath ^mpich', installed=any), [])
 
         # mpich ref count updated properly.
         mpich_rec = self.installed_db.get_record('mpich')
@@ -282,14 +282,16 @@ class DatabaseTest(MockDatabase):
 
         with self.installed_db.read_transaction():
             self.assertEqual(
-                len(self.installed_db.query('mpileaks ^zmpi', installed=any)), 1)
+                len(self.installed_db.query('mpileaks ^zmpi', installed=any)),
+                1)
 
         self.assertRaises(Exception, fail_while_writing)
 
         # reload DB and make sure zmpi is still there.
         with self.installed_db.read_transaction():
             self.assertEqual(
-                len(self.installed_db.query('mpileaks ^zmpi', installed=any)), 1)
+                len(self.installed_db.query('mpileaks ^zmpi', installed=any)),
+                1)
 
     def test_110_no_write_with_exception_on_install(self):
         def fail_while_writing():
diff --git a/lib/spack/spack/test/file_cache.py b/lib/spack/spack/test/file_cache.py
index 6142b135eb..cc66beda2e 100644
--- a/lib/spack/spack/test/file_cache.py
+++ b/lib/spack/spack/test/file_cache.py
@@ -30,7 +30,6 @@ import shutil
 import tempfile
 import unittest
 
-import spack
 from spack.file_cache import FileCache
 
 
diff --git a/lib/spack/spack/test/lock.py b/lib/spack/spack/test/lock.py
index aaf573241b..b24050aa74 100644
--- a/lib/spack/spack/test/lock.py
+++ b/lib/spack/spack/test/lock.py
@@ -46,21 +46,21 @@ class LockTest(unittest.TestCase):
         self.lock_path = join_path(self.tempdir, 'lockfile')
         touch(self.lock_path)
 
-
     def tearDown(self):
-         shutil.rmtree(self.tempdir, ignore_errors=True)
-
+        shutil.rmtree(self.tempdir, ignore_errors=True)
 
     def multiproc_test(self, *functions):
         """Order some processes using simple barrier synchronization."""
         b = Barrier(len(functions), timeout=barrier_timeout)
         procs = [Process(target=f, args=(b,)) for f in functions]
-        for p in procs: p.start()
+
+        for p in procs:
+            p.start()
+
         for p in procs:
             p.join()
             self.assertEqual(p.exitcode, 0)
 
-
     #
     # Process snippets below can be composed into tests.
     #
@@ -68,27 +68,26 @@ class LockTest(unittest.TestCase):
         lock = Lock(self.lock_path)
         lock.acquire_write()  # grab exclusive lock
         barrier.wait()
-        barrier.wait() # hold the lock until exception raises in other procs.
+        barrier.wait()  # hold the lock until exception raises in other procs.
 
     def acquire_read(self, barrier):
         lock = Lock(self.lock_path)
         lock.acquire_read()  # grab shared lock
         barrier.wait()
-        barrier.wait() # hold the lock until exception raises in other procs.
+        barrier.wait()  # hold the lock until exception raises in other procs.
 
     def timeout_write(self, barrier):
         lock = Lock(self.lock_path)
-        barrier.wait() # wait for lock acquire in first process
+        barrier.wait()  # wait for lock acquire in first process
         self.assertRaises(LockError, lock.acquire_write, 0.1)
         barrier.wait()
 
     def timeout_read(self, barrier):
         lock = Lock(self.lock_path)
-        barrier.wait() # wait for lock acquire in first process
+        barrier.wait()  # wait for lock acquire in first process
         self.assertRaises(LockError, lock.acquire_read, 0.1)
         barrier.wait()
 
-
     #
     # Test that exclusive locks on other processes time out when an
     # exclusive lock is held.
@@ -97,11 +96,13 @@ class LockTest(unittest.TestCase):
         self.multiproc_test(self.acquire_write, self.timeout_write)
 
     def test_write_lock_timeout_on_write_2(self):
-        self.multiproc_test(self.acquire_write, self.timeout_write, self.timeout_write)
+        self.multiproc_test(
+            self.acquire_write, self.timeout_write, self.timeout_write)
 
     def test_write_lock_timeout_on_write_3(self):
-        self.multiproc_test(self.acquire_write, self.timeout_write, self.timeout_write, self.timeout_write)
-
+        self.multiproc_test(
+            self.acquire_write, self.timeout_write, self.timeout_write,
+            self.timeout_write)
 
     #
     # Test that shared locks on other processes time out when an
@@ -111,11 +112,13 @@ class LockTest(unittest.TestCase):
         self.multiproc_test(self.acquire_write, self.timeout_read)
 
     def test_read_lock_timeout_on_write_2(self):
-        self.multiproc_test(self.acquire_write, self.timeout_read, self.timeout_read)
+        self.multiproc_test(
+            self.acquire_write, self.timeout_read, self.timeout_read)
 
     def test_read_lock_timeout_on_write_3(self):
-        self.multiproc_test(self.acquire_write, self.timeout_read, self.timeout_read, self.timeout_read)
-
+        self.multiproc_test(
+            self.acquire_write, self.timeout_read, self.timeout_read,
+            self.timeout_read)
 
     #
     # Test that exclusive locks time out when shared locks are held.
@@ -124,27 +127,35 @@ class LockTest(unittest.TestCase):
         self.multiproc_test(self.acquire_read, self.timeout_write)
 
     def test_write_lock_timeout_on_read_2(self):
-        self.multiproc_test(self.acquire_read, self.timeout_write, self.timeout_write)
+        self.multiproc_test(
+            self.acquire_read, self.timeout_write, self.timeout_write)
 
     def test_write_lock_timeout_on_read_3(self):
-        self.multiproc_test(self.acquire_read, self.timeout_write, self.timeout_write, self.timeout_write)
-
+        self.multiproc_test(
+            self.acquire_read, self.timeout_write, self.timeout_write,
+            self.timeout_write)
 
     #
     # Test that exclusive locks time while lots of shared locks are held.
     #
     def test_write_lock_timeout_with_multiple_readers_2_1(self):
-        self.multiproc_test(self.acquire_read, self.acquire_read, self.timeout_write)
+        self.multiproc_test(
+            self.acquire_read, self.acquire_read, self.timeout_write)
 
     def test_write_lock_timeout_with_multiple_readers_2_2(self):
-        self.multiproc_test(self.acquire_read, self.acquire_read, self.timeout_write, self.timeout_write)
+        self.multiproc_test(
+            self.acquire_read, self.acquire_read, self.timeout_write,
+            self.timeout_write)
 
     def test_write_lock_timeout_with_multiple_readers_3_1(self):
-        self.multiproc_test(self.acquire_read, self.acquire_read, self.acquire_read, self.timeout_write)
+        self.multiproc_test(
+            self.acquire_read, self.acquire_read, self.acquire_read,
+            self.timeout_write)
 
     def test_write_lock_timeout_with_multiple_readers_3_2(self):
-        self.multiproc_test(self.acquire_read, self.acquire_read, self.acquire_read, self.timeout_write, self.timeout_write)
-
+        self.multiproc_test(
+            self.acquire_read, self.acquire_read, self.acquire_read,
+            self.timeout_write, self.timeout_write)
 
     #
     # Longer test case that ensures locks are reusable. Ordering is
@@ -155,108 +166,108 @@ class LockTest(unittest.TestCase):
             lock = Lock(self.lock_path)
 
             lock.acquire_write()
-            barrier.wait() # ---------------------------------------- 1
+            barrier.wait()  # ---------------------------------------- 1
             # others test timeout
-            barrier.wait() # ---------------------------------------- 2
+            barrier.wait()  # ---------------------------------------- 2
             lock.release_write()   # release and others acquire read
-            barrier.wait() # ---------------------------------------- 3
+            barrier.wait()  # ---------------------------------------- 3
             self.assertRaises(LockError, lock.acquire_write, 0.1)
             lock.acquire_read()
-            barrier.wait() # ---------------------------------------- 4
+            barrier.wait()  # ---------------------------------------- 4
             lock.release_read()
-            barrier.wait() # ---------------------------------------- 5
+            barrier.wait()  # ---------------------------------------- 5
 
             # p2 upgrades read to write
-            barrier.wait() # ---------------------------------------- 6
+            barrier.wait()  # ---------------------------------------- 6
             self.assertRaises(LockError, lock.acquire_write, 0.1)
             self.assertRaises(LockError, lock.acquire_read, 0.1)
-            barrier.wait() # ---------------------------------------- 7
+            barrier.wait()  # ---------------------------------------- 7
             # p2 releases write and read
-            barrier.wait() # ---------------------------------------- 8
+            barrier.wait()  # ---------------------------------------- 8
 
             # p3 acquires read
-            barrier.wait() # ---------------------------------------- 9
+            barrier.wait()  # ---------------------------------------- 9
             # p3 upgrades read to write
-            barrier.wait() # ---------------------------------------- 10
+            barrier.wait()  # ---------------------------------------- 10
             self.assertRaises(LockError, lock.acquire_write, 0.1)
             self.assertRaises(LockError, lock.acquire_read, 0.1)
-            barrier.wait() # ---------------------------------------- 11
+            barrier.wait()  # ---------------------------------------- 11
             # p3 releases locks
-            barrier.wait() # ---------------------------------------- 12
+            barrier.wait()  # ---------------------------------------- 12
             lock.acquire_read()
-            barrier.wait() # ---------------------------------------- 13
+            barrier.wait()  # ---------------------------------------- 13
             lock.release_read()
 
         def p2(barrier):
             lock = Lock(self.lock_path)
 
             # p1 acquires write
-            barrier.wait() # ---------------------------------------- 1
+            barrier.wait()  # ---------------------------------------- 1
             self.assertRaises(LockError, lock.acquire_write, 0.1)
             self.assertRaises(LockError, lock.acquire_read, 0.1)
-            barrier.wait() # ---------------------------------------- 2
+            barrier.wait()  # ---------------------------------------- 2
             lock.acquire_read()
-            barrier.wait() # ---------------------------------------- 3
+            barrier.wait()  # ---------------------------------------- 3
             # p1 tests shared read
-            barrier.wait() # ---------------------------------------- 4
+            barrier.wait()  # ---------------------------------------- 4
             # others release reads
-            barrier.wait() # ---------------------------------------- 5
+            barrier.wait()  # ---------------------------------------- 5
 
-            lock.acquire_write() # upgrade read to write
-            barrier.wait() # ---------------------------------------- 6
+            lock.acquire_write()  # upgrade read to write
+            barrier.wait()  # ---------------------------------------- 6
             # others test timeout
-            barrier.wait() # ---------------------------------------- 7
+            barrier.wait()  # ---------------------------------------- 7
             lock.release_write()  # release read AND write (need both)
             lock.release_read()
-            barrier.wait() # ---------------------------------------- 8
+            barrier.wait()  # ---------------------------------------- 8
 
             # p3 acquires read
-            barrier.wait() # ---------------------------------------- 9
+            barrier.wait()  # ---------------------------------------- 9
             # p3 upgrades read to write
-            barrier.wait() # ---------------------------------------- 10
+            barrier.wait()  # ---------------------------------------- 10
             self.assertRaises(LockError, lock.acquire_write, 0.1)
             self.assertRaises(LockError, lock.acquire_read, 0.1)
-            barrier.wait() # ---------------------------------------- 11
+            barrier.wait()  # ---------------------------------------- 11
             # p3 releases locks
-            barrier.wait() # ---------------------------------------- 12
+            barrier.wait()  # ---------------------------------------- 12
             lock.acquire_read()
-            barrier.wait() # ---------------------------------------- 13
+            barrier.wait()  # ---------------------------------------- 13
             lock.release_read()
 
         def p3(barrier):
             lock = Lock(self.lock_path)
 
             # p1 acquires write
-            barrier.wait() # ---------------------------------------- 1
+            barrier.wait()  # ---------------------------------------- 1
             self.assertRaises(LockError, lock.acquire_write, 0.1)
             self.assertRaises(LockError, lock.acquire_read, 0.1)
-            barrier.wait() # ---------------------------------------- 2
+            barrier.wait()  # ---------------------------------------- 2
             lock.acquire_read()
-            barrier.wait() # ---------------------------------------- 3
+            barrier.wait()  # ---------------------------------------- 3
             # p1 tests shared read
-            barrier.wait() # ---------------------------------------- 4
+            barrier.wait()  # ---------------------------------------- 4
             lock.release_read()
-            barrier.wait() # ---------------------------------------- 5
+            barrier.wait()  # ---------------------------------------- 5
 
             # p2 upgrades read to write
-            barrier.wait() # ---------------------------------------- 6
+            barrier.wait()  # ---------------------------------------- 6
             self.assertRaises(LockError, lock.acquire_write, 0.1)
             self.assertRaises(LockError, lock.acquire_read, 0.1)
-            barrier.wait() # ---------------------------------------- 7
+            barrier.wait()  # ---------------------------------------- 7
             # p2 releases write & read
-            barrier.wait() # ---------------------------------------- 8
+            barrier.wait()  # ---------------------------------------- 8
 
             lock.acquire_read()
-            barrier.wait() # ---------------------------------------- 9
+            barrier.wait()  # ---------------------------------------- 9
             lock.acquire_write()
-            barrier.wait() # ---------------------------------------- 10
+            barrier.wait()  # ---------------------------------------- 10
             # others test timeout
-            barrier.wait() # ---------------------------------------- 11
+            barrier.wait()  # ---------------------------------------- 11
             lock.release_read()   # release read AND write in opposite
             lock.release_write()  # order from before on p2
-            barrier.wait() # ---------------------------------------- 12
+            barrier.wait()  # ---------------------------------------- 12
             lock.acquire_read()
-            barrier.wait() # ---------------------------------------- 13
+            barrier.wait()  # ---------------------------------------- 13
             lock.release_read()
 
         self.multiproc_test(p1, p2, p3)
@@ -270,14 +281,18 @@ class LockTest(unittest.TestCase):
             vals['exception'] = (t or v or tb)
 
         lock = Lock(self.lock_path)
-        vals = {'entered': False, 'exited': False, 'exception': False }
-        with ReadTransaction(lock, enter_fn, exit_fn): pass
+        vals = {'entered': False, 'exited': False, 'exception': False}
+        with ReadTransaction(lock, enter_fn, exit_fn):
+            pass
+
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
         self.assertFalse(vals['exception'])
 
-        vals = {'entered': False, 'exited': False, 'exception': False }
-        with WriteTransaction(lock, enter_fn, exit_fn): pass
+        vals = {'entered': False, 'exited': False, 'exception': False}
+        with WriteTransaction(lock, enter_fn, exit_fn):
+            pass
+
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
         self.assertFalse(vals['exception'])
@@ -300,13 +315,13 @@ class LockTest(unittest.TestCase):
             with WriteTransaction(lock, enter_fn, exit_fn):
                 raise Exception()
 
-        vals = {'entered': False, 'exited': False, 'exception': False }
+        vals = {'entered': False, 'exited': False, 'exception': False}
         self.assertRaises(Exception, do_read_with_exception)
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
         self.assertTrue(vals['exception'])
 
-        vals = {'entered': False, 'exited': False, 'exception': False }
+        vals = {'entered': False, 'exited': False, 'exception': False}
         self.assertRaises(Exception, do_write_with_exception)
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
@@ -328,8 +343,10 @@ class LockTest(unittest.TestCase):
         lock = Lock(self.lock_path)
 
         vals = {'entered': False, 'exited': False, 'exited_fn': False,
-                'exception': False, 'exception_fn': False }
-        with ReadTransaction(lock, TestContextManager, exit_fn): pass
+                'exception': False, 'exception_fn': False}
+        with ReadTransaction(lock, TestContextManager, exit_fn):
+            pass
+
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
         self.assertFalse(vals['exception'])
@@ -337,8 +354,10 @@ class LockTest(unittest.TestCase):
         self.assertFalse(vals['exception_fn'])
 
         vals = {'entered': False, 'exited': False, 'exited_fn': False,
-                'exception': False, 'exception_fn': False }
-        with ReadTransaction(lock, TestContextManager): pass
+                'exception': False, 'exception_fn': False}
+        with ReadTransaction(lock, TestContextManager):
+            pass
+
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
         self.assertFalse(vals['exception'])
@@ -346,8 +365,10 @@ class LockTest(unittest.TestCase):
         self.assertFalse(vals['exception_fn'])
 
         vals = {'entered': False, 'exited': False, 'exited_fn': False,
-                'exception': False, 'exception_fn': False }
-        with WriteTransaction(lock, TestContextManager, exit_fn): pass
+                'exception': False, 'exception_fn': False}
+        with WriteTransaction(lock, TestContextManager, exit_fn):
+            pass
+
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
         self.assertFalse(vals['exception'])
@@ -355,8 +376,10 @@ class LockTest(unittest.TestCase):
         self.assertFalse(vals['exception_fn'])
 
         vals = {'entered': False, 'exited': False, 'exited_fn': False,
-                'exception': False, 'exception_fn': False }
-        with WriteTransaction(lock, TestContextManager): pass
+                'exception': False, 'exception_fn': False}
+        with WriteTransaction(lock, TestContextManager):
+            pass
+
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
         self.assertFalse(vals['exception'])
@@ -387,7 +410,7 @@ class LockTest(unittest.TestCase):
                 raise Exception()
 
         vals = {'entered': False, 'exited': False, 'exited_fn': False,
-                'exception': False, 'exception_fn': False }
+                'exception': False, 'exception_fn': False}
         self.assertRaises(Exception, do_read_with_exception, exit_fn)
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
@@ -396,7 +419,7 @@ class LockTest(unittest.TestCase):
         self.assertTrue(vals['exception_fn'])
 
         vals = {'entered': False, 'exited': False, 'exited_fn': False,
-                'exception': False, 'exception_fn': False }
+                'exception': False, 'exception_fn': False}
         self.assertRaises(Exception, do_read_with_exception, None)
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
@@ -405,7 +428,7 @@ class LockTest(unittest.TestCase):
         self.assertFalse(vals['exception_fn'])
 
         vals = {'entered': False, 'exited': False, 'exited_fn': False,
-                'exception': False, 'exception_fn': False }
+                'exception': False, 'exception_fn': False}
         self.assertRaises(Exception, do_write_with_exception, exit_fn)
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
@@ -414,7 +437,7 @@ class LockTest(unittest.TestCase):
         self.assertTrue(vals['exception_fn'])
 
         vals = {'entered': False, 'exited': False, 'exited_fn': False,
-                'exception': False, 'exception_fn': False }
+                'exception': False, 'exception_fn': False}
         self.assertRaises(Exception, do_write_with_exception, None)
         self.assertTrue(vals['entered'])
         self.assertTrue(vals['exited'])
diff --git a/lib/spack/spack/test/provider_index.py b/lib/spack/spack/test/provider_index.py
index 861814e0ae..9847dd05a6 100644
--- a/lib/spack/spack/test/provider_index.py
+++ b/lib/spack/spack/test/provider_index.py
@@ -22,27 +22,28 @@
 # License along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ##############################################################################
+"""Tests for provider index cache files.
+
+Tests assume that mock packages provide this:
+
+  {'blas':   {
+       blas: set([netlib-blas, openblas, openblas-with-lapack])},
+   'lapack': {lapack: set([netlib-lapack, openblas-with-lapack])},
+   'mpi': {mpi@:1: set([mpich@:1]),
+                    mpi@:2.0: set([mpich2]),
+                    mpi@:2.1: set([mpich2@1.1:]),
+                    mpi@:2.2: set([mpich2@1.2:]),
+                    mpi@:3: set([mpich@3:]),
+                    mpi@:10.0: set([zmpi])},
+    'stuff': {stuff: set([externalvirtual])}}
+"""
 from StringIO import StringIO
-import unittest
 
 import spack
 from spack.spec import Spec
 from spack.provider_index import ProviderIndex
 from spack.test.mock_packages_test import *
 
-# Test assume that mock packages provide this:
-#
-# {'blas':   {
-#      blas: set([netlib-blas, openblas, openblas-with-lapack])},
-#  'lapack': {lapack: set([netlib-lapack, openblas-with-lapack])},
-#  'mpi': {mpi@:1: set([mpich@:1]),
-#                   mpi@:2.0: set([mpich2]),
-#                   mpi@:2.1: set([mpich2@1.1:]),
-#                   mpi@:2.2: set([mpich2@1.2:]),
-#                   mpi@:3: set([mpich@3:]),
-#                   mpi@:10.0: set([zmpi])},
-#   'stuff': {stuff: set([externalvirtual])}}
-#
 
 class ProviderIndexTest(MockPackagesTest):
 
@@ -57,7 +58,6 @@ class ProviderIndexTest(MockPackagesTest):
 
         self.assertEqual(p, q)
 
-
     def test_providers_for_simple(self):
         p = ProviderIndex(spack.repo.all_package_names())
 
@@ -70,7 +70,6 @@ class ProviderIndexTest(MockPackagesTest):
         self.assertTrue(Spec('netlib-lapack') in lapack_providers)
         self.assertTrue(Spec('openblas-with-lapack') in lapack_providers)
 
-
     def test_mpi_providers(self):
         p = ProviderIndex(spack.repo.all_package_names())
 
@@ -83,13 +82,11 @@ class ProviderIndexTest(MockPackagesTest):
         self.assertTrue(Spec('mpich@3:') in mpi_3_providers)
         self.assertTrue(Spec('zmpi') in mpi_3_providers)
 
-
     def test_equal(self):
         p = ProviderIndex(spack.repo.all_package_names())
         q = ProviderIndex(spack.repo.all_package_names())
         self.assertEqual(p, q)
 
-
     def test_copy(self):
         p = ProviderIndex(spack.repo.all_package_names())
         q = p.copy()
diff --git a/lib/spack/spack/test/spec_yaml.py b/lib/spack/spack/test/spec_yaml.py
index fc0ce0b2f3..964aea9422 100644
--- a/lib/spack/spack/test/spec_yaml.py
+++ b/lib/spack/spack/test/spec_yaml.py
@@ -30,6 +30,7 @@ YAML format preserves DAG informatoin in the spec.
 from spack.spec import Spec
 from spack.test.mock_packages_test import *
 
+
 class SpecYamlTest(MockPackagesTest):
 
     def check_yaml_round_trip(self, spec):
@@ -37,30 +38,25 @@ class SpecYamlTest(MockPackagesTest):
         spec_from_yaml = Spec.from_yaml(yaml_text)
         self.assertTrue(spec.eq_dag(spec_from_yaml))
 
-
     def test_simple_spec(self):
         spec = Spec('mpileaks')
         self.check_yaml_round_trip(spec)
 
-
     def test_normal_spec(self):
         spec = Spec('mpileaks+debug~opt')
         spec.normalize()
         self.check_yaml_round_trip(spec)
 
-
     def test_ambiguous_version_spec(self):
         spec = Spec('mpileaks@1.0:5.0,6.1,7.3+debug~opt')
         spec.normalize()
         self.check_yaml_round_trip(spec)
 
-
     def test_concrete_spec(self):
         spec = Spec('mpileaks+debug~opt')
         spec.concretize()
         self.check_yaml_round_trip(spec)
 
-
     def test_yaml_subdag(self):
         spec = Spec('mpileaks^mpich+debug')
         spec.concretize()