Stop using `six` in Spack (#33905)

Since we dropped support for Python 2.7, there's no need
so use `six` anymore. We still need to vendor it until
we update our vendored dependencies.

7 files changed, 32 insertions, 51 deletions

diff --git a/lib/spack/llnl/util/argparsewriter.py b/lib/spack/llnl/util/argparsewriter.py
index a8db508c2f..ad5bf3e83d 100644
--- a/lib/spack/llnl/util/argparsewriter.py
+++ b/lib/spack/llnl/util/argparsewriter.py
@@ -7,11 +7,10 @@ from __future__ import print_function
 
 import argparse
 import errno
+import io
 import re
 import sys
 
-from six import StringIO
-
 
 class Command(object):
     """Parsed representation of a command from argparse.
@@ -181,7 +180,7 @@ class ArgparseRstWriter(ArgparseWriter):
         self.rst_levels = rst_levels
 
     def format(self, cmd):
-        string = StringIO()
+        string = io.StringIO()
         string.write(self.begin_command(cmd.prog))
 
         if cmd.description:
diff --git a/lib/spack/llnl/util/filesystem.py b/lib/spack/llnl/util/filesystem.py
index 30ecc1ebc8..db83cea6fc 100644
--- a/lib/spack/llnl/util/filesystem.py
+++ b/lib/spack/llnl/util/filesystem.py
@@ -18,8 +18,6 @@ import tempfile
 from contextlib import contextmanager
 from sys import platform as _platform
 
-import six
-
 from llnl.util import tty
 from llnl.util.lang import dedupe, memoized
 from llnl.util.symlink import islink, symlink
@@ -520,7 +518,7 @@ def chgrp(path, group, follow_symlinks=True):
     if is_windows:
         raise OSError("Function 'chgrp' is not supported on Windows")
 
-    if isinstance(group, six.string_types):
+    if isinstance(group, str):
         gid = grp.getgrnam(group).gr_gid
     else:
         gid = group
@@ -1017,7 +1015,7 @@ def open_if_filename(str_or_file, mode="r"):
 
     If it's a file object, just yields the file object.
     """
-    if isinstance(str_or_file, six.string_types):
+    if isinstance(str_or_file, str):
         with open(str_or_file, mode) as f:
             yield f
     else:
@@ -1602,7 +1600,7 @@ def find(root, files, recursive=True):
     Returns:
         list: The files that have been found
     """
-    if isinstance(files, six.string_types):
+    if isinstance(files, str):
         files = [files]
 
     if recursive:
@@ -1666,7 +1664,7 @@ class FileList(collections.abc.Sequence):
     """
 
     def __init__(self, files):
-        if isinstance(files, six.string_types):
+        if isinstance(files, str):
             files = [files]
 
         self.files = list(dedupe(files))
@@ -1762,7 +1760,7 @@ class HeaderList(FileList):
     def directories(self, value):
         value = value or []
         # Accept a single directory as input
-        if isinstance(value, six.string_types):
+        if isinstance(value, str):
             value = [value]
 
         self._directories = [path_to_os_path(os.path.normpath(x))[0] for x in value]
@@ -1898,7 +1896,7 @@ def find_headers(headers, root, recursive=False):
     Returns:
         HeaderList: The headers that have been found
     """
-    if isinstance(headers, six.string_types):
+    if isinstance(headers, str):
         headers = [headers]
     elif not isinstance(headers, collections.abc.Sequence):
         message = "{0} expects a string or sequence of strings as the "
@@ -2064,7 +2062,7 @@ def find_system_libraries(libraries, shared=True):
     Returns:
         LibraryList: The libraries that have been found
     """
-    if isinstance(libraries, six.string_types):
+    if isinstance(libraries, str):
         libraries = [libraries]
     elif not isinstance(libraries, collections.abc.Sequence):
         message = "{0} expects a string or sequence of strings as the "
@@ -2121,7 +2119,7 @@ def find_libraries(libraries, root, shared=True, recursive=False, runtime=True):
     Returns:
         LibraryList: The libraries that have been found
     """
-    if isinstance(libraries, six.string_types):
+    if isinstance(libraries, str):
         libraries = [libraries]
     elif not isinstance(libraries, collections.abc.Sequence):
         message = "{0} expects a string or sequence of strings as the "
diff --git a/lib/spack/llnl/util/lang.py b/lib/spack/llnl/util/lang.py
index d8f3cc9b9b..6deb224d70 100644
--- a/lib/spack/llnl/util/lang.py
+++ b/lib/spack/llnl/util/lang.py
@@ -17,9 +17,6 @@ import traceback
 from datetime import datetime, timedelta
 from typing import Any, Callable, Iterable, List, Tuple
 
-import six
-from six import string_types
-
 # Ignore emacs backups when listing modules
 ignore_modules = [r"^\.#", "~$"]
 
@@ -200,14 +197,9 @@ def memoized(func):
             return ret
         except TypeError as e:
             # TypeError is raised when indexing into a dict if the key is unhashable.
-            raise six.raise_from(
-                UnhashableArguments(
-                    "args + kwargs '{}' was not hashable for function '{}'".format(
-                        key, func.__name__
-                    ),
-                ),
-                e,
-            )
+            raise UnhashableArguments(
+                "args + kwargs '{}' was not hashable for function '{}'".format(key, func.__name__),
+            ) from e
 
     return _memoized_function
 
@@ -574,7 +566,7 @@ def match_predicate(*args):
 
     def match(string):
         for arg in args:
-            if isinstance(arg, string_types):
+            if isinstance(arg, str):
                 if re.search(arg, string):
                     return True
             elif isinstance(arg, list) or isinstance(arg, tuple):
diff --git a/lib/spack/llnl/util/tty/__init__.py b/lib/spack/llnl/util/tty/__init__.py
index 7c86411dbe..4b289438fa 100644
--- a/lib/spack/llnl/util/tty/__init__.py
+++ b/lib/spack/llnl/util/tty/__init__.py
@@ -6,6 +6,7 @@
 from __future__ import unicode_literals
 
 import contextlib
+import io
 import os
 import struct
 import sys
@@ -14,10 +15,6 @@ import traceback
 from datetime import datetime
 from sys import platform as _platform
 
-import six
-from six import StringIO
-from six.moves import input
-
 if _platform != "win32":
     import fcntl
     import termios
@@ -183,7 +180,7 @@ def msg(message, *args, **kwargs):
     else:
         cwrite("@*b{%s==>} %s%s" % (st_text, get_timestamp(), cescape(_output_filter(message))))
     for arg in args:
-        print(indent + _output_filter(six.text_type(arg)))
+        print(indent + _output_filter(str(arg)))
 
 
 def info(message, *args, **kwargs):
@@ -201,13 +198,13 @@ def info(message, *args, **kwargs):
         st_text = process_stacktrace(st_countback)
     cprint(
         "@%s{%s==>} %s%s"
-        % (format, st_text, get_timestamp(), cescape(_output_filter(six.text_type(message)))),
+        % (format, st_text, get_timestamp(), cescape(_output_filter(str(message)))),
         stream=stream,
     )
     for arg in args:
         if wrap:
             lines = textwrap.wrap(
-                _output_filter(six.text_type(arg)),
+                _output_filter(str(arg)),
                 initial_indent=indent,
                 subsequent_indent=indent,
                 break_long_words=break_long_words,
@@ -215,7 +212,7 @@ def info(message, *args, **kwargs):
             for line in lines:
                 stream.write(line + "\n")
         else:
-            stream.write(indent + _output_filter(six.text_type(arg)) + "\n")
+            stream.write(indent + _output_filter(str(arg)) + "\n")
 
 
 def verbose(message, *args, **kwargs):
@@ -238,7 +235,7 @@ def error(message, *args, **kwargs):
 
     kwargs.setdefault("format", "*r")
     kwargs.setdefault("stream", sys.stderr)
-    info("Error: " + six.text_type(message), *args, **kwargs)
+    info("Error: " + str(message), *args, **kwargs)
 
 
 def warn(message, *args, **kwargs):
@@ -247,7 +244,7 @@ def warn(message, *args, **kwargs):
 
     kwargs.setdefault("format", "*Y")
     kwargs.setdefault("stream", sys.stderr)
-    info("Warning: " + six.text_type(message), *args, **kwargs)
+    info("Warning: " + str(message), *args, **kwargs)
 
 
 def die(message, *args, **kwargs):
@@ -271,7 +268,7 @@ def get_number(prompt, **kwargs):
     while number is None:
         msg(prompt, newline=False)
         ans = input()
-        if ans == six.text_type(abort):
+        if ans == str(abort):
             return None
 
         if ans:
@@ -336,11 +333,11 @@ def hline(label=None, **kwargs):
         cols -= 2
     cols = min(max_width, cols)
 
-    label = six.text_type(label)
+    label = str(label)
     prefix = char * 2 + " "
     suffix = " " + (cols - len(prefix) - clen(label)) * char
 
-    out = StringIO()
+    out = io.StringIO()
     out.write(prefix)
     out.write(label)
     out.write(suffix)
diff --git a/lib/spack/llnl/util/tty/colify.py b/lib/spack/llnl/util/tty/colify.py
index 73c1daf0d5..4520aad38f 100644
--- a/lib/spack/llnl/util/tty/colify.py
+++ b/lib/spack/llnl/util/tty/colify.py
@@ -8,11 +8,10 @@ Routines for printing columnar output.  See ``colify()`` for more information.
 """
 from __future__ import division, unicode_literals
 
+import io
 import os
 import sys
 
-from six import StringIO, text_type
-
 from llnl.util.tty import terminal_size
 from llnl.util.tty.color import cextra, clen
 
@@ -134,7 +133,7 @@ def colify(elts, **options):
         )
 
     # elts needs to be an array of strings so we can count the elements
-    elts = [text_type(elt) for elt in elts]
+    elts = [str(elt) for elt in elts]
     if not elts:
         return (0, ())
 
@@ -232,7 +231,7 @@ def colify_table(table, **options):
 def colified(elts, **options):
     """Invokes the ``colify()`` function but returns the result as a string
     instead of writing it to an output string."""
-    sio = StringIO()
+    sio = io.StringIO()
     options["output"] = sio
     colify(elts, **options)
     return sio.getvalue()
diff --git a/lib/spack/llnl/util/tty/color.py b/lib/spack/llnl/util/tty/color.py
index ad6862fc28..83e8316914 100644
--- a/lib/spack/llnl/util/tty/color.py
+++ b/lib/spack/llnl/util/tty/color.py
@@ -65,8 +65,6 @@ import re
 import sys
 from contextlib import contextmanager
 
-import six
-
 
 class ColorParseError(Exception):
     """Raised when a color format fails to parse."""
@@ -259,7 +257,7 @@ def cescape(string):
     Returns:
         (str): the string with color codes escaped
     """
-    string = six.text_type(string)
+    string = str(string)
     string = string.replace("@", "@@")
     string = string.replace("}", "}}")
     return string
diff --git a/lib/spack/llnl/util/tty/log.py b/lib/spack/llnl/util/tty/log.py
index 2d6609c390..0b79dd01ac 100644
--- a/lib/spack/llnl/util/tty/log.py
+++ b/lib/spack/llnl/util/tty/log.py
@@ -24,8 +24,6 @@ from threading import Thread
 from types import ModuleType  # novm
 from typing import Optional  # novm
 
-from six import StringIO, string_types
-
 import llnl.util.tty as tty
 
 termios = None  # type: Optional[ModuleType]
@@ -308,7 +306,7 @@ class FileWrapper(object):
 
         self.file_like = file_like
 
-        if isinstance(file_like, string_types):
+        if isinstance(file_like, str):
             self.open = True
         elif _file_descriptors_work(file_like):
             self.open = False
@@ -324,7 +322,7 @@ class FileWrapper(object):
             if self.file_like:
                 self.file = open(self.file_like, "w", encoding="utf-8")
             else:
-                self.file = StringIO()
+                self.file = io.StringIO()
             return self.file
         else:
             # We were handed an already-open file object. In this case we also
@@ -787,7 +785,7 @@ class winlog(object):
             raise RuntimeError("file argument must be set by __init__ ")
 
         # Open both write and reading on logfile
-        if type(self.logfile) == StringIO:
+        if type(self.logfile) == io.StringIO:
             self._ioflag = True
             # cannot have two streams on tempfile, so we must make our own
             sys.stdout = self.logfile
@@ -1013,7 +1011,7 @@ def _writer_daemon(
 
     finally:
         # send written data back to parent if we used a StringIO
-        if isinstance(log_file, StringIO):
+        if isinstance(log_file, io.StringIO):
             control_pipe.send(log_file.getvalue())
         log_file_wrapper.close()
         close_connection_and_file(read_multiprocess_fd, in_pipe)