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- """Compatibility wrappers for Py2/Py3."""
-
- import sys
- import os
-
- if sys.version_info[0] < 3:
- from UserDict import UserDict, IterableUserDict
- from urllib import quote
- from urllib import quote_plus
- from urllib import unquote as urllib_unquote
- from urllib import urlopen
- from urlparse import urlparse
-
- def unquote(uri):
- """Specialized unquote that uses UTF-8 for parsing."""
- uri = uri.encode('ascii')
- unquoted = urllib_unquote(uri)
- return unquoted.decode('utf-8')
-
- # Old-style of re-raising an exception is SyntaxError in Python 3,
- # so hide behind exec() so the Python 3 parser doesn't see it
- exec('''def reraise(exc_type, exc_value, exc_traceback):
- """Re-raise an exception given information from sys.exc_info()
-
- Note that unlike six.reraise, this does not support replacing the
- traceback. All arguments must come from a single sys.exc_info() call.
- """
- raise exc_type, exc_value, exc_traceback
- ''')
-
- else:
- from collections import UserDict
- IterableUserDict = UserDict
- from urllib.parse import quote, quote_plus, unquote, urlparse
- from urllib.request import urlopen
-
- def reraise(exc_type, exc_value, exc_traceback):
- """Re-raise an exception given information from sys.exc_info()
-
- Note that unlike six.reraise, this does not support replacing the
- traceback. All arguments must come from a single sys.exc_info() call.
- """
- # In Python 3, all exception info is contained in one object.
- raise exc_value
-
- try:
- from shutil import which
- except ImportError:
- # shutil.which() from Python 3.6
- # "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
- # 2011, 2012, 2013, 2014, 2015, 2016, 2017 Python Software Foundation;
- # All Rights Reserved"
- def which(cmd, mode=os.F_OK | os.X_OK, path=None):
- """Given a command, mode, and a PATH string, return the path which
- conforms to the given mode on the PATH, or None if there is no such
- file.
-
- `mode` defaults to os.F_OK | os.X_OK. `path` defaults to the result
- of os.environ.get("PATH"), or can be overridden with a custom search
- path.
-
- """
- # Check that a given file can be accessed with the correct mode.
- # Additionally check that `file` is not a directory, as on Windows
- # directories pass the os.access check.
- def _access_check(fn, mode):
- return (os.path.exists(fn) and os.access(fn, mode)
- and not os.path.isdir(fn))
-
- # If we're given a path with a directory part, look it up directly rather
- # than referring to PATH directories. This includes checking relative to the
- # current directory, e.g. ./script
- if os.path.dirname(cmd):
- if _access_check(cmd, mode):
- return cmd
- return None
-
- if path is None:
- path = os.environ.get("PATH", os.defpath)
- if not path:
- return None
- path = path.split(os.pathsep)
-
- if sys.platform == "win32":
- # The current directory takes precedence on Windows.
- if not os.curdir in path:
- path.insert(0, os.curdir)
-
- # PATHEXT is necessary to check on Windows.
- pathext = os.environ.get("PATHEXT", "").split(os.pathsep)
- # See if the given file matches any of the expected path extensions.
- # This will allow us to short circuit when given "python.exe".
- # If it does match, only test that one, otherwise we have to try
- # others.
- if any(cmd.lower().endswith(ext.lower()) for ext in pathext):
- files = [cmd]
- else:
- files = [cmd + ext for ext in pathext]
- else:
- # On other platforms you don't have things like PATHEXT to tell you
- # what file suffixes are executable, so just pass on cmd as-is.
- files = [cmd]
-
- seen = set()
- for dir in path:
- normdir = os.path.normcase(dir)
- if not normdir in seen:
- seen.add(normdir)
- for thefile in files:
- name = os.path.join(dir, thefile)
- if _access_check(name, mode):
- return name
- return None
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