flake8: fix flake8 issues with invalid escapes

- in many files, regular strings were used in places where raw strings
  should've been used.

- convert these to raw strings and get rid of new flake8 errors

6 files changed, 81 insertions, 81 deletions

diff --git a/lib/spack/spack/directory_layout.py b/lib/spack/spack/directory_layout.py
index f152442781..f579d5664b 100644
--- a/lib/spack/spack/directory_layout.py
+++ b/lib/spack/spack/directory_layout.py
@@ -171,7 +171,7 @@ class YamlDirectoryLayout(DirectoryLayout):
             "${COMPILERNAME}-${COMPILERVER}/"
             "${PACKAGE}-${VERSION}-${HASH}")
         if self.hash_len is not None:
-            if re.search('\${HASH:\d+}', self.path_scheme):
+            if re.search(r'\${HASH:\d+}', self.path_scheme):
                 raise InvalidDirectoryLayoutParametersError(
                     "Conflicting options for installation layout hash length")
             self.path_scheme = self.path_scheme.replace(
diff --git a/lib/spack/spack/graph.py b/lib/spack/spack/graph.py
index 5c8c60a3bb..8c481084ae 100644
--- a/lib/spack/spack/graph.py
+++ b/lib/spack/spack/graph.py
@@ -3,7 +3,7 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
-"""Functions for graphing DAGs of dependencies.
+r"""Functions for graphing DAGs of dependencies.
 
 This file contains code for graphing DAGs of software packages
 (i.e. Spack specs).  There are two main functions you probably care
diff --git a/lib/spack/spack/relocate.py b/lib/spack/spack/relocate.py
index 8e9a48208c..a559ae6495 100644
--- a/lib/spack/spack/relocate.py
+++ b/lib/spack/spack/relocate.py
@@ -120,7 +120,7 @@ def macho_get_paths(path_name):
         if match:
             lhs = match.group(1).lstrip().rstrip()
             rhs = match.group(2)
-            match2 = re.search('(.*) \(.*\)', rhs)
+            match2 = re.search(r'(.*) \(.*\)', rhs)
             if match2:
                 rhs = match2.group(1)
             if lhs == 'cmd':
diff --git a/lib/spack/spack/test/cmd/license.py b/lib/spack/spack/test/cmd/license.py
index bc77cad096..fe02cb18a5 100644
--- a/lib/spack/spack/test/cmd/license.py
+++ b/lib/spack/spack/test/cmd/license.py
@@ -61,8 +61,8 @@ def test_verify(tmpdir):
     assert str(old_lgpl_header) in out
     assert str(correct_header) not in out
     assert '3 improperly licensed files' in out
-    assert re.search('files with no SPDX-License-Identifier:\s*1', out)
-    assert re.search('files with wrong SPDX-License-Identifier:\s*1', out)
-    assert re.search('files with old license header:\s*1', out)
+    assert re.search(r'files with no SPDX-License-Identifier:\s*1', out)
+    assert re.search(r'files with wrong SPDX-License-Identifier:\s*1', out)
+    assert re.search(r'files with old license header:\s*1', out)
 
     assert license.returncode == 1
diff --git a/lib/spack/spack/test/pattern.py b/lib/spack/spack/test/pattern.py
index 1e3fbdaf0e..406915bdf0 100644
--- a/lib/spack/spack/test/pattern.py
+++ b/lib/spack/spack/test/pattern.py
@@ -15,10 +15,10 @@ def interface():
         counter = 0
 
         def add(self):
-            raise NotImplemented('add not implemented')
+            raise NotImplementedError('add not implemented')
 
         def subtract(self):
-            raise NotImplemented('subtract not implemented')
+            raise NotImplementedError('subtract not implemented')
 
     return Base
 
diff --git a/lib/spack/spack/url.py b/lib/spack/spack/url.py
index 5819d07e1a..387c8c957d 100644
--- a/lib/spack/spack/url.py
+++ b/lib/spack/spack/url.py
@@ -44,7 +44,7 @@ from spack.version import Version
 # "path" seemed like the most generic term.
 #
 def find_list_url(url):
-    """Finds a good list URL for the supplied URL.
+    r"""Finds a good list URL for the supplied URL.
 
     By default, returns the dirname of the archive path.
 
@@ -148,81 +148,81 @@ def strip_version_suffixes(path):
 
     suffix_regexes = [
         # Download type
-        '[Ii]nstall',
-        'all',
-        'code',
-        'src(_0)?',
-        '[Ss]ources?',
-        'file',
-        'full',
-        'single',
-        'public',
-        'with[a-zA-Z_-]+',
-        'bin',
-        'binary',
-        'run',
-        '[Uu]niversal',
-        'jar',
-        'complete',
-        'dynamic',
-        'oss',
-        'gem',
-        'tar',
-        'sh',
+        r'[Ii]nstall',
+        r'all',
+        r'code',
+        r'src(_0)?',
+        r'[Ss]ources?',
+        r'file',
+        r'full',
+        r'single',
+        r'public',
+        r'with[a-zA-Z_-]+',
+        r'bin',
+        r'binary',
+        r'run',
+        r'[Uu]niversal',
+        r'jar',
+        r'complete',
+        r'dynamic',
+        r'oss',
+        r'gem',
+        r'tar',
+        r'sh',
 
         # Download version
-        'release',
-        'stable',
-        '[Ff]inal',
-        'rel',
-        'orig',
-        'dist',
-        '\+',
+        r'release',
+        r'stable',
+        r'[Ff]inal',
+        r'rel',
+        r'orig',
+        r'dist',
+        r'\+',
 
         # License
-        'gpl',
+        r'gpl',
 
         # Arch
         # Needs to come before and after OS, appears in both orders
-        'ia32',
-        'intel',
-        'amd64',
-        'x64',
-        'x86[_-]64',
-        'x86',
-        'i[36]86',
-        'ppc64(le)?',
-        'armv?(7l|6l|64)',
+        r'ia32',
+        r'intel',
+        r'amd64',
+        r'x64',
+        r'x86[_-]64',
+        r'x86',
+        r'i[36]86',
+        r'ppc64(le)?',
+        r'armv?(7l|6l|64)',
 
         # OS
-        '[Ll]inux(_64)?',
-        '[Uu]ni?x',
-        '[Ss]un[Oo][Ss]',
-        '[Mm]ac[Oo][Ss][Xx]?',
-        '[Oo][Ss][Xx]',
-        '[Dd]arwin(64)?',
-        '[Aa]pple',
-        '[Ww]indows',
-        '[Ww]in(64|32)?',
-        '[Cc]ygwin(64|32)?',
-        '[Mm]ingw',
+        r'[Ll]inux(_64)?',
+        r'[Uu]ni?x',
+        r'[Ss]un[Oo][Ss]',
+        r'[Mm]ac[Oo][Ss][Xx]?',
+        r'[Oo][Ss][Xx]',
+        r'[Dd]arwin(64)?',
+        r'[Aa]pple',
+        r'[Ww]indows',
+        r'[Ww]in(64|32)?',
+        r'[Cc]ygwin(64|32)?',
+        r'[Mm]ingw',
 
         # Arch
         # Needs to come before and after OS, appears in both orders
-        'ia32',
-        'intel',
-        'amd64',
-        'x64',
-        'x86[_-]64',
-        'x86',
-        'i[36]86',
-        'ppc64(le)?',
-        'armv?(7l|6l|64)?',
+        r'ia32',
+        r'intel',
+        r'amd64',
+        r'x64',
+        r'x86[_-]64',
+        r'x86',
+        r'i[36]86',
+        r'ppc64(le)?',
+        r'armv?(7l|6l|64)?',
 
         # PyPI
-        '[._-]py[23].*\.whl',
-        '[._-]cp[23].*\.whl',
-        '[._-]win.*\.exe',
+        r'[._-]py[23].*\.whl',
+        r'[._-]cp[23].*\.whl',
+        r'[._-]win.*\.exe',
     ]
 
     for regex in suffix_regexes:
@@ -274,22 +274,22 @@ def strip_name_suffixes(path, version):
         str(version) + '.*',
 
         # Download type
-        'install',
-        'src',
-        '(open)?[Ss]ources?',
-        '[._-]archive',
-        '[._-]std',
+        r'install',
+        r'src',
+        r'(open)?[Ss]ources?',
+        r'[._-]archive',
+        r'[._-]std',
 
         # Download version
-        'release',
-        'snapshot',
-        'distrib',
+        r'release',
+        r'snapshot',
+        r'distrib',
 
         # VCS
-        '0\+bzr',
+        r'0\+bzr',
 
         # License
-        'gpl',
+        r'gpl',
     ]
 
     for regex in suffix_regexes:
@@ -799,7 +799,7 @@ def wildcard_version(path):
 
     # Replace each version with a generic capture group to find versions
     # and escape everything else so it's not interpreted as a regex
-    result = '(\d.*)'.join(re.escape(vp) for vp in vparts)
+    result = r'(\d.*)'.join(re.escape(vp) for vp in vparts)
 
     return result