Lib/site.py - platform/external/python/cpython3 - Gitiles

 """Append module search paths for third-party packages to sys.path.

 ****************************************************************
 * This module is automatically imported during initialization. *
 ****************************************************************

 This will append site-specific paths to the module search path.  On
 Unix (including Mac OSX), it starts with sys.prefix and
 sys.exec_prefix (if different) and appends
 lib/python<version>/site-packages.
 On other platforms (such as Windows), it tries each of the
 prefixes directly, as well as with lib/site-packages appended.  The
 resulting directories, if they exist, are appended to sys.path, and
 also inspected for path configuration files.

 If a file named "pyvenv.cfg" exists one directory above sys.executable,
 sys.prefix and sys.exec_prefix are set to that directory and
 it is also checked for site-packages (sys.base_prefix and
 sys.base_exec_prefix will always be the "real" prefixes of the Python
 installation). If "pyvenv.cfg" (a bootstrap configuration file) contains
 the key "include-system-site-packages" set to anything other than "false"
 (case-insensitive), the system-level prefixes will still also be
 searched for site-packages; otherwise they won't.

 All of the resulting site-specific directories, if they exist, are
 appended to sys.path, and also inspected for path configuration
 files.

 A path configuration file is a file whose name has the form
 <package>.pth; its contents are additional directories (one per line)
 to be added to sys.path.  Non-existing directories (or
 non-directories) are never added to sys.path; no directory is added to
 sys.path more than once.  Blank lines and lines beginning with
 '#' are skipped. Lines starting with 'import' are executed.

 For example, suppose sys.prefix and sys.exec_prefix are set to
 /usr/local and there is a directory /usr/local/lib/python2.5/site-packages
 with three subdirectories, foo, bar and spam, and two path
 configuration files, foo.pth and bar.pth.  Assume foo.pth contains the
 following:

   # foo package configuration
   foo
   bar
   bletch

 and bar.pth contains:

   # bar package configuration
   bar

 Then the following directories are added to sys.path, in this order:

   /usr/local/lib/python2.5/site-packages/bar
   /usr/local/lib/python2.5/site-packages/foo

 Note that bletch is omitted because it doesn't exist; bar precedes foo
 because bar.pth comes alphabetically before foo.pth; and spam is
 omitted because it is not mentioned in either path configuration file.

 The readline module is also automatically configured to enable
 completion for systems that support it.  This can be overriden in
 sitecustomize, usercustomize or PYTHONSTARTUP.

 After these operations, an attempt is made to import a module
 named sitecustomize, which can perform arbitrary additional
 site-specific customizations.  If this import fails with an
 ImportError exception, it is silently ignored.
 """

 import sys
 import os
 import builtins
 import _sitebuiltins

 # Prefixes for site-packages; add additional prefixes like /usr/local here
 PREFIXES = [sys.prefix, sys.exec_prefix]
 # Enable per user site-packages directory
 # set it to False to disable the feature or True to force the feature
 ENABLE_USER_SITE = None

 # for distutils.commands.install
 # These values are initialized by the getuserbase() and getusersitepackages()
 # functions, through the main() function when Python starts.
 USER_SITE = None
 USER_BASE = None


 def makepath(*paths):
     dir = os.path.join(*paths)
     try:
         dir = os.path.abspath(dir)
     except OSError:
         pass
     return dir, os.path.normcase(dir)


 def abs_paths():
     """Set all module __file__ and __cached__ attributes to an absolute path"""
     for m in set(sys.modules.values()):
         if (getattr(getattr(m, '__loader__', None), '__module__', None) not in
                 ('_frozen_importlib', '_frozen_importlib_external')):
             continue   # don't mess with a PEP 302-supplied __file__
         try:
             m.__file__ = os.path.abspath(m.__file__)
         except (AttributeError, OSError):
             pass
         try:
             m.__cached__ = os.path.abspath(m.__cached__)
         except (AttributeError, OSError):
             pass


 def removeduppaths():
     """ Remove duplicate entries from sys.path along with making them
     absolute"""
     # This ensures that the initial path provided by the interpreter contains
     # only absolute pathnames, even if we're running from the build directory.
     L = []
     known_paths = set()
     for dir in sys.path:
         # Filter out duplicate paths (on case-insensitive file systems also
         # if they only differ in case); turn relative paths into absolute
         # paths.
         dir, dircase = makepath(dir)
         if not dircase in known_paths:
             L.append(dir)
             known_paths.add(dircase)
     sys.path[:] = L
     return known_paths


 def _init_pathinfo():
     """Return a set containing all existing directory entries from sys.path"""
     d = set()
     for dir in sys.path:
         try:
             if os.path.isdir(dir):
                 dir, dircase = makepath(dir)
                 d.add(dircase)
         except TypeError:
             continue
     return d


 def addpackage(sitedir, name, known_paths):
     """Process a .pth file within the site-packages directory:
        For each line in the file, either combine it with sitedir to a path
        and add that to known_paths, or execute it if it starts with 'import '.
     """
     if known_paths is None:
         known_paths = _init_pathinfo()
         reset = 1
     else:
         reset = 0
     fullname = os.path.join(sitedir, name)
     try:
         f = open(fullname, "r")
     except OSError:
         return
     with f:
         for n, line in enumerate(f):
             if line.startswith("#"):
                 continue
             try:
                 if line.startswith(("import ", "import\t")):
                     exec(line)
                     continue
                 line = line.rstrip()
                 dir, dircase = makepath(sitedir, line)
                 if not dircase in known_paths and os.path.exists(dir):
                     sys.path.append(dir)
                     known_paths.add(dircase)
             except Exception:
                 print("Error processing line {:d} of {}:\n".format(n+1, fullname),
                       file=sys.stderr)
                 import traceback
                 for record in traceback.format_exception(*sys.exc_info()):
                     for line in record.splitlines():
                         print('  '+line, file=sys.stderr)
                 print("\nRemainder of file ignored", file=sys.stderr)
                 break
     if reset:
         known_paths = None
     return known_paths


 def addsitedir(sitedir, known_paths=None):
     """Add 'sitedir' argument to sys.path if missing and handle .pth files in
     'sitedir'"""
     if known_paths is None:
         known_paths = _init_pathinfo()
         reset = 1
     else:
         reset = 0
     sitedir, sitedircase = makepath(sitedir)
     if not sitedircase in known_paths:
         sys.path.append(sitedir)        # Add path component
         known_paths.add(sitedircase)
     try:
         names = os.listdir(sitedir)
     except OSError:
         return
     names = [name for name in names if name.endswith(".pth")]
     for name in sorted(names):
         addpackage(sitedir, name, known_paths)
     if reset:
         known_paths = None
     return known_paths


 def check_enableusersite():
     """Check if user site directory is safe for inclusion

     The function tests for the command line flag (including environment var),
     process uid/gid equal to effective uid/gid.

     None: Disabled for security reasons
     False: Disabled by user (command line option)
     True: Safe and enabled
     """
     if sys.flags.no_user_site:
         return False

     if hasattr(os, "getuid") and hasattr(os, "geteuid"):
         # check process uid == effective uid
         if os.geteuid() != os.getuid():
             return None
     if hasattr(os, "getgid") and hasattr(os, "getegid"):
         # check process gid == effective gid
         if os.getegid() != os.getgid():
             return None

     return True

 def getuserbase():
     """Returns the `user base` directory path.

     The `user base` directory can be used to store data. If the global
     variable ``USER_BASE`` is not initialized yet, this function will also set
     it.
     """
     global USER_BASE
     if USER_BASE is not None:
         return USER_BASE
     from sysconfig import get_config_var
     USER_BASE = get_config_var('userbase')
     return USER_BASE

 def getusersitepackages():
     """Returns the user-specific site-packages directory path.

     If the global variable ``USER_SITE`` is not initialized yet, this
     function will also set it.
     """
     global USER_SITE
     user_base = getuserbase() # this will also set USER_BASE

     if USER_SITE is not None:
         return USER_SITE

     from sysconfig import get_path

     if sys.platform == 'darwin':
         from sysconfig import get_config_var
         if get_config_var('PYTHONFRAMEWORK'):
             USER_SITE = get_path('purelib', 'osx_framework_user')
             return USER_SITE

     USER_SITE = get_path('purelib', '%s_user' % os.name)
     return USER_SITE

 def addusersitepackages(known_paths):
     """Add a per user site-package to sys.path

     Each user has its own python directory with site-packages in the
     home directory.
     """
     # get the per user site-package path
     # this call will also make sure USER_BASE and USER_SITE are set
     user_site = getusersitepackages()

     if ENABLE_USER_SITE and os.path.isdir(user_site):
         addsitedir(user_site, known_paths)
     return known_paths

 def getsitepackages(prefixes=None):
     """Returns a list containing all global site-packages directories.

     For each directory present in ``prefixes`` (or the global ``PREFIXES``),
     this function will find its `site-packages` subdirectory depending on the
     system environment, and will return a list of full paths.
     """
     sitepackages = []
     seen = set()

     if prefixes is None:
         prefixes = PREFIXES

     for prefix in prefixes:
         if not prefix or prefix in seen:
             continue
         seen.add(prefix)

         if os.sep == '/':
             sitepackages.append(os.path.join(prefix, "lib",
                                         "python" + sys.version[:3],
                                         "site-packages"))
         else:
             sitepackages.append(prefix)
             sitepackages.append(os.path.join(prefix, "lib", "site-packages"))
         if sys.platform == "darwin":
             # for framework builds *only* we add the standard Apple
             # locations.
             from sysconfig import get_config_var
             framework = get_config_var("PYTHONFRAMEWORK")
             if framework:
                 sitepackages.append(
                         os.path.join("/Library", framework,
                             sys.version[:3], "site-packages"))
     return sitepackages

 def addsitepackages(known_paths, prefixes=None):
     """Add site-packages to sys.path"""
     for sitedir in getsitepackages(prefixes):
         if os.path.isdir(sitedir):
             addsitedir(sitedir, known_paths)

     return known_paths

 def setquit():
     """Define new builtins 'quit' and 'exit'.

     These are objects which make the interpreter exit when called.
     The repr of each object contains a hint at how it works.

     """
     if os.sep == ':':
         eof = 'Cmd-Q'
     elif os.sep == '\\':
         eof = 'Ctrl-Z plus Return'
     else:
         eof = 'Ctrl-D (i.e. EOF)'

     builtins.quit = _sitebuiltins.Quitter('quit', eof)
     builtins.exit = _sitebuiltins.Quitter('exit', eof)


 def setcopyright():
     """Set 'copyright' and 'credits' in builtins"""
     builtins.copyright = _sitebuiltins._Printer("copyright", sys.copyright)
     if sys.platform[:4] == 'java':
         builtins.credits = _sitebuiltins._Printer(
             "credits",
             "Jython is maintained by the Jython developers (www.jython.org).")
     else:
         builtins.credits = _sitebuiltins._Printer("credits", """\
     Thanks to CWI, CNRI, BeOpen.com, Zope Corporation and a cast of thousands
     for supporting Python development.  See www.python.org for more information.""")
     files, dirs = [], []
     # Not all modules are required to have a __file__ attribute.  See
     # PEP 420 for more details.
     if hasattr(os, '__file__'):
         here = os.path.dirname(os.__file__)
         files.extend(["LICENSE.txt", "LICENSE"])
         dirs.extend([os.path.join(here, os.pardir), here, os.curdir])
     builtins.license = _sitebuiltins._Printer(
         "license",
         "See https://www.python.org/psf/license/",
         files, dirs)


 def sethelper():
     builtins.help = _sitebuiltins._Helper()

 def enablerlcompleter():
     """Enable default readline configuration on interactive prompts, by
     registering a sys.__interactivehook__.

     If the readline module can be imported, the hook will set the Tab key
     as completion key and register ~/.python_history as history file.
     This can be overriden in the sitecustomize or usercustomize module,
     or in a PYTHONSTARTUP file.
     """
     def register_readline():
         import atexit
         try:
             import readline
             import rlcompleter
         except ImportError:
             return

         # Reading the initialization (config) file may not be enough to set a
         # completion key, so we set one first and then read the file.
         readline_doc = getattr(readline, '__doc__', '')
         if readline_doc is not None and 'libedit' in readline_doc:
             readline.parse_and_bind('bind ^I rl_complete')
         else:
             readline.parse_and_bind('tab: complete')

         try:
             readline.read_init_file()
         except OSError:
             # An OSError here could have many causes, but the most likely one
             # is that there's no .inputrc file (or .editrc file in the case of
             # Mac OS X + libedit) in the expected location.  In that case, we
             # want to ignore the exception.
             pass

         if readline.get_current_history_length() == 0:
             # If no history was loaded, default to .python_history.
             # The guard is necessary to avoid doubling history size at
             # each interpreter exit when readline was already configured
             # through a PYTHONSTARTUP hook, see:
             # http://bugs.python.org/issue5845#msg198636
             history = os.path.join(os.path.expanduser('~'),
                                    '.python_history')
             try:
                 readline.read_history_file(history)
             except IOError:
                 pass
             atexit.register(readline.write_history_file, history)

     sys.__interactivehook__ = register_readline

 def aliasmbcs():
     """On Windows, some default encodings are not provided by Python,
     while they are always available as "mbcs" in each locale. Make
     them usable by aliasing to "mbcs" in such a case."""
     if sys.platform == 'win32':
         import _bootlocale, codecs
         enc = _bootlocale.getpreferredencoding(False)
         if enc.startswith('cp'):            # "cp***" ?
             try:
                 codecs.lookup(enc)
             except LookupError:
                 import encodings
                 encodings._cache[enc] = encodings._unknown
                 encodings.aliases.aliases[enc] = 'mbcs'

 CONFIG_LINE = r'^(?P<key>(\w|[-_])+)\s*=\s*(?P<value>.*)\s*$'

 def venv(known_paths):
     global PREFIXES, ENABLE_USER_SITE

     env = os.environ
     if sys.platform == 'darwin' and '__PYVENV_LAUNCHER__' in env:
         executable = os.environ['__PYVENV_LAUNCHER__']
     else:
         executable = sys.executable
     exe_dir, _ = os.path.split(os.path.abspath(executable))
     site_prefix = os.path.dirname(exe_dir)
     sys._home = None
     conf_basename = 'pyvenv.cfg'
     candidate_confs = [
         conffile for conffile in (
             os.path.join(exe_dir, conf_basename),
             os.path.join(site_prefix, conf_basename)
             )
         if os.path.isfile(conffile)
         ]

     if candidate_confs:
         import re
         config_line = re.compile(CONFIG_LINE)
         virtual_conf = candidate_confs[0]
         system_site = "true"
         with open(virtual_conf) as f:
             for line in f:
                 line = line.strip()
                 m = config_line.match(line)
                 if m:
                     d = m.groupdict()
                     key, value = d['key'].lower(), d['value']
                     if key == 'include-system-site-packages':
                         system_site = value.lower()
                     elif key == 'home':
                         sys._home = value

         sys.prefix = sys.exec_prefix = site_prefix

         # Doing this here ensures venv takes precedence over user-site
         addsitepackages(known_paths, [sys.prefix])

         # addsitepackages will process site_prefix again if its in PREFIXES,
         # but that's ok; known_paths will prevent anything being added twice
         if system_site == "true":
             PREFIXES.insert(0, sys.prefix)
         else:
             PREFIXES = [sys.prefix]
             ENABLE_USER_SITE = False

     return known_paths


 def execsitecustomize():
     """Run custom site specific code, if available."""
     try:
         import sitecustomize
     except ImportError:
         pass
     except Exception as err:
         if os.environ.get("PYTHONVERBOSE"):
             sys.excepthook(*sys.exc_info())
         else:
             sys.stderr.write(
                 "Error in sitecustomize; set PYTHONVERBOSE for traceback:\n"
                 "%s: %s\n" %
                 (err.__class__.__name__, err))


 def execusercustomize():
     """Run custom user specific code, if available."""
     try:
         import usercustomize
     except ImportError:
         pass
     except Exception as err:
         if os.environ.get("PYTHONVERBOSE"):
             sys.excepthook(*sys.exc_info())
         else:
             sys.stderr.write(
                 "Error in usercustomize; set PYTHONVERBOSE for traceback:\n"
                 "%s: %s\n" %
                 (err.__class__.__name__, err))


 def main():
     """Add standard site-specific directories to the module search path.

     This function is called automatically when this module is imported,
     unless the python interpreter was started with the -S flag.
     """
     global ENABLE_USER_SITE

     abs_paths()
     known_paths = removeduppaths()
     known_paths = venv(known_paths)
     if ENABLE_USER_SITE is None:
         ENABLE_USER_SITE = check_enableusersite()
     known_paths = addusersitepackages(known_paths)
     known_paths = addsitepackages(known_paths)
     setquit()
     setcopyright()
     sethelper()
     enablerlcompleter()
     aliasmbcs()
     execsitecustomize()
     if ENABLE_USER_SITE:
         execusercustomize()

 # Prevent edition of sys.path when python was started with -S and
 # site is imported later.
 if not sys.flags.no_site:
     main()

 def _script():
     help = """\
     %s [--user-base] [--user-site]

     Without arguments print some useful information
     With arguments print the value of USER_BASE and/or USER_SITE separated
     by '%s'.

     Exit codes with --user-base or --user-site:
       0 - user site directory is enabled
       1 - user site directory is disabled by user
       2 - uses site directory is disabled by super user
           or for security reasons
      >2 - unknown error
     """
     args = sys.argv[1:]
     if not args:
         user_base = getuserbase()
         user_site = getusersitepackages()
         print("sys.path = [")
         for dir in sys.path:
             print("    %r," % (dir,))
         print("]")
         print("USER_BASE: %r (%s)" % (user_base,
             "exists" if os.path.isdir(user_base) else "doesn't exist"))
         print("USER_SITE: %r (%s)" % (user_site,
             "exists" if os.path.isdir(user_site) else "doesn't exist"))
         print("ENABLE_USER_SITE: %r" %  ENABLE_USER_SITE)
         sys.exit(0)

     buffer = []
     if '--user-base' in args:
         buffer.append(USER_BASE)
     if '--user-site' in args:
         buffer.append(USER_SITE)

     if buffer:
         print(os.pathsep.join(buffer))
         if ENABLE_USER_SITE:
             sys.exit(0)
         elif ENABLE_USER_SITE is False:
             sys.exit(1)
         elif ENABLE_USER_SITE is None:
             sys.exit(2)
         else:
             sys.exit(3)
     else:
         import textwrap
         print(textwrap.dedent(help % (sys.argv[0], os.pathsep)))
         sys.exit(10)

 if __name__ == '__main__':
     _script()
	"""Append module search paths for third-party packages to sys.path.

	****************************************************************
	* This module is automatically imported during initialization. *
	****************************************************************

	This will append site-specific paths to the module search path. On
	Unix (including Mac OSX), it starts with sys.prefix and
	sys.exec_prefix (if different) and appends
	lib/python<version>/site-packages.
	On other platforms (such as Windows), it tries each of the
	prefixes directly, as well as with lib/site-packages appended. The
	resulting directories, if they exist, are appended to sys.path, and
	also inspected for path configuration files.

	If a file named "pyvenv.cfg" exists one directory above sys.executable,
	sys.prefix and sys.exec_prefix are set to that directory and
	it is also checked for site-packages (sys.base_prefix and
	sys.base_exec_prefix will always be the "real" prefixes of the Python
	installation). If "pyvenv.cfg" (a bootstrap configuration file) contains
	the key "include-system-site-packages" set to anything other than "false"
	(case-insensitive), the system-level prefixes will still also be
	searched for site-packages; otherwise they won't.

	All of the resulting site-specific directories, if they exist, are
	appended to sys.path, and also inspected for path configuration
	files.

	A path configuration file is a file whose name has the form
	<package>.pth; its contents are additional directories (one per line)
	to be added to sys.path. Non-existing directories (or
	non-directories) are never added to sys.path; no directory is added to
	sys.path more than once. Blank lines and lines beginning with
	'#' are skipped. Lines starting with 'import' are executed.

	For example, suppose sys.prefix and sys.exec_prefix are set to
	/usr/local and there is a directory /usr/local/lib/python2.5/site-packages
	with three subdirectories, foo, bar and spam, and two path
	configuration files, foo.pth and bar.pth. Assume foo.pth contains the
	following:

	# foo package configuration
	foo
	bar
	bletch

	and bar.pth contains:

	# bar package configuration
	bar

	Then the following directories are added to sys.path, in this order:

	/usr/local/lib/python2.5/site-packages/bar
	/usr/local/lib/python2.5/site-packages/foo

	Note that bletch is omitted because it doesn't exist; bar precedes foo
	because bar.pth comes alphabetically before foo.pth; and spam is
	omitted because it is not mentioned in either path configuration file.

	The readline module is also automatically configured to enable
	completion for systems that support it. This can be overriden in
	sitecustomize, usercustomize or PYTHONSTARTUP.

	After these operations, an attempt is made to import a module
	named sitecustomize, which can perform arbitrary additional
	site-specific customizations. If this import fails with an
	ImportError exception, it is silently ignored.
	"""

	import sys
	import os
	import builtins
	import _sitebuiltins

	# Prefixes for site-packages; add additional prefixes like /usr/local here
	PREFIXES = [sys.prefix, sys.exec_prefix]
	# Enable per user site-packages directory
	# set it to False to disable the feature or True to force the feature
	ENABLE_USER_SITE = None

	# for distutils.commands.install
	# These values are initialized by the getuserbase() and getusersitepackages()
	# functions, through the main() function when Python starts.
	USER_SITE = None
	USER_BASE = None


	def makepath(*paths):
	dir = os.path.join(*paths)
	try:
	dir = os.path.abspath(dir)
	except OSError:
	pass
	return dir, os.path.normcase(dir)


	def abs_paths():
	"""Set all module __file__ and __cached__ attributes to an absolute path"""
	for m in set(sys.modules.values()):
	if (getattr(getattr(m, '__loader__', None), '__module__', None) not in
	('_frozen_importlib', '_frozen_importlib_external')):
	continue # don't mess with a PEP 302-supplied __file__
	try:
	m.__file__ = os.path.abspath(m.__file__)
	except (AttributeError, OSError):
	pass
	try:
	m.__cached__ = os.path.abspath(m.__cached__)
	except (AttributeError, OSError):
	pass


	def removeduppaths():
	""" Remove duplicate entries from sys.path along with making them
	absolute"""
	# This ensures that the initial path provided by the interpreter contains
	# only absolute pathnames, even if we're running from the build directory.
	L = []
	known_paths = set()
	for dir in sys.path:
	# Filter out duplicate paths (on case-insensitive file systems also
	# if they only differ in case); turn relative paths into absolute
	# paths.
	dir, dircase = makepath(dir)
	if not dircase in known_paths:
	L.append(dir)
	known_paths.add(dircase)
	sys.path[:] = L
	return known_paths


	def _init_pathinfo():
	"""Return a set containing all existing directory entries from sys.path"""
	d = set()
	for dir in sys.path:
	try:
	if os.path.isdir(dir):
	dir, dircase = makepath(dir)
	d.add(dircase)
	except TypeError:
	continue
	return d


	def addpackage(sitedir, name, known_paths):
	"""Process a .pth file within the site-packages directory:
	For each line in the file, either combine it with sitedir to a path
	and add that to known_paths, or execute it if it starts with 'import '.
	"""
	if known_paths is None:
	known_paths = _init_pathinfo()
	reset = 1
	else:
	reset = 0
	fullname = os.path.join(sitedir, name)
	try:
	f = open(fullname, "r")
	except OSError:
	return
	with f:
	for n, line in enumerate(f):
	if line.startswith("#"):
	continue
	try:
	if line.startswith(("import ", "import\t")):
	exec(line)
	continue
	line = line.rstrip()
	dir, dircase = makepath(sitedir, line)
	if not dircase in known_paths and os.path.exists(dir):
	sys.path.append(dir)
	known_paths.add(dircase)
	except Exception:
	print("Error processing line {:d} of {}:\n".format(n+1, fullname),
	file=sys.stderr)
	import traceback
	for record in traceback.format_exception(*sys.exc_info()):
	for line in record.splitlines():
	print(' '+line, file=sys.stderr)
	print("\nRemainder of file ignored", file=sys.stderr)
	break
	if reset:
	known_paths = None
	return known_paths


	def addsitedir(sitedir, known_paths=None):
	"""Add 'sitedir' argument to sys.path if missing and handle .pth files in
	'sitedir'"""
	if known_paths is None:
	known_paths = _init_pathinfo()
	reset = 1
	else:
	reset = 0
	sitedir, sitedircase = makepath(sitedir)
	if not sitedircase in known_paths:
	sys.path.append(sitedir) # Add path component
	known_paths.add(sitedircase)
	try:
	names = os.listdir(sitedir)
	except OSError:
	return
	names = [name for name in names if name.endswith(".pth")]
	for name in sorted(names):
	addpackage(sitedir, name, known_paths)
	if reset:
	known_paths = None
	return known_paths


	def check_enableusersite():
	"""Check if user site directory is safe for inclusion

	The function tests for the command line flag (including environment var),
	process uid/gid equal to effective uid/gid.

	None: Disabled for security reasons
	False: Disabled by user (command line option)
	True: Safe and enabled
	"""
	if sys.flags.no_user_site:
	return False

	if hasattr(os, "getuid") and hasattr(os, "geteuid"):
	# check process uid == effective uid
	if os.geteuid() != os.getuid():
	return None
	if hasattr(os, "getgid") and hasattr(os, "getegid"):
	# check process gid == effective gid
	if os.getegid() != os.getgid():
	return None

	return True

	def getuserbase():
	"""Returns the `user base` directory path.

	The `user base` directory can be used to store data. If the global
	variable ``USER_BASE`` is not initialized yet, this function will also set
	it.
	"""
	global USER_BASE
	if USER_BASE is not None:
	return USER_BASE
	from sysconfig import get_config_var
	USER_BASE = get_config_var('userbase')
	return USER_BASE

	def getusersitepackages():
	"""Returns the user-specific site-packages directory path.

	If the global variable ``USER_SITE`` is not initialized yet, this
	function will also set it.
	"""
	global USER_SITE
	user_base = getuserbase() # this will also set USER_BASE

	if USER_SITE is not None:
	return USER_SITE

	from sysconfig import get_path

	if sys.platform == 'darwin':
	from sysconfig import get_config_var
	if get_config_var('PYTHONFRAMEWORK'):
	USER_SITE = get_path('purelib', 'osx_framework_user')
	return USER_SITE

	USER_SITE = get_path('purelib', '%s_user' % os.name)
	return USER_SITE

	def addusersitepackages(known_paths):
	"""Add a per user site-package to sys.path

	Each user has its own python directory with site-packages in the
	home directory.
	"""
	# get the per user site-package path
	# this call will also make sure USER_BASE and USER_SITE are set
	user_site = getusersitepackages()

	if ENABLE_USER_SITE and os.path.isdir(user_site):
	addsitedir(user_site, known_paths)
	return known_paths

	def getsitepackages(prefixes=None):
	"""Returns a list containing all global site-packages directories.

	For each directory present in ``prefixes`` (or the global ``PREFIXES``),
	this function will find its `site-packages` subdirectory depending on the
	system environment, and will return a list of full paths.
	"""
	sitepackages = []
	seen = set()

	if prefixes is None:
	prefixes = PREFIXES

	for prefix in prefixes:
	if not prefix or prefix in seen:
	continue
	seen.add(prefix)

	if os.sep == '/':
	sitepackages.append(os.path.join(prefix, "lib",
	"python" + sys.version[:3],
	"site-packages"))
	else:
	sitepackages.append(prefix)
	sitepackages.append(os.path.join(prefix, "lib", "site-packages"))
	if sys.platform == "darwin":
	# for framework builds only we add the standard Apple
	# locations.
	from sysconfig import get_config_var
	framework = get_config_var("PYTHONFRAMEWORK")
	if framework:
	sitepackages.append(
	os.path.join("/Library", framework,
	sys.version[:3], "site-packages"))
	return sitepackages

	def addsitepackages(known_paths, prefixes=None):
	"""Add site-packages to sys.path"""
	for sitedir in getsitepackages(prefixes):
	if os.path.isdir(sitedir):
	addsitedir(sitedir, known_paths)

	return known_paths

	def setquit():
	"""Define new builtins 'quit' and 'exit'.

	These are objects which make the interpreter exit when called.
	The repr of each object contains a hint at how it works.

	"""
	if os.sep == ':':
	eof = 'Cmd-Q'
	elif os.sep == '\\':
	eof = 'Ctrl-Z plus Return'
	else:
	eof = 'Ctrl-D (i.e. EOF)'

	builtins.quit = _sitebuiltins.Quitter('quit', eof)
	builtins.exit = _sitebuiltins.Quitter('exit', eof)


	def setcopyright():
	"""Set 'copyright' and 'credits' in builtins"""
	builtins.copyright = _sitebuiltins._Printer("copyright", sys.copyright)
	if sys.platform[:4] == 'java':
	builtins.credits = _sitebuiltins._Printer(
	"credits",
	"Jython is maintained by the Jython developers (www.jython.org).")
	else:
	builtins.credits = _sitebuiltins._Printer("credits", """\
	Thanks to CWI, CNRI, BeOpen.com, Zope Corporation and a cast of thousands
	for supporting Python development. See www.python.org for more information.""")
	files, dirs = [], []
	# Not all modules are required to have a __file__ attribute. See
	# PEP 420 for more details.
	if hasattr(os, '__file__'):
	here = os.path.dirname(os.__file__)
	files.extend(["LICENSE.txt", "LICENSE"])
	dirs.extend([os.path.join(here, os.pardir), here, os.curdir])
	builtins.license = _sitebuiltins._Printer(
	"license",
	"See https://www.python.org/psf/license/",
	files, dirs)


	def sethelper():
	builtins.help = _sitebuiltins._Helper()

	def enablerlcompleter():
	"""Enable default readline configuration on interactive prompts, by
	registering a sys.__interactivehook__.

	If the readline module can be imported, the hook will set the Tab key
	as completion key and register ~/.python_history as history file.
	This can be overriden in the sitecustomize or usercustomize module,
	or in a PYTHONSTARTUP file.
	"""
	def register_readline():
	import atexit
	try:
	import readline
	import rlcompleter
	except ImportError:
	return

	# Reading the initialization (config) file may not be enough to set a
	# completion key, so we set one first and then read the file.
	readline_doc = getattr(readline, '__doc__', '')
	if readline_doc is not None and 'libedit' in readline_doc:
	readline.parse_and_bind('bind ^I rl_complete')
	else:
	readline.parse_and_bind('tab: complete')

	try:
	readline.read_init_file()
	except OSError:
	# An OSError here could have many causes, but the most likely one
	# is that there's no .inputrc file (or .editrc file in the case of
	# Mac OS X + libedit) in the expected location. In that case, we
	# want to ignore the exception.
	pass

	if readline.get_current_history_length() == 0:
	# If no history was loaded, default to .python_history.
	# The guard is necessary to avoid doubling history size at
	# each interpreter exit when readline was already configured
	# through a PYTHONSTARTUP hook, see:
	# http://bugs.python.org/issue5845#msg198636
	history = os.path.join(os.path.expanduser('~'),
	'.python_history')
	try:
	readline.read_history_file(history)
	except IOError:
	pass
	atexit.register(readline.write_history_file, history)

	sys.__interactivehook__ = register_readline

	def aliasmbcs():
	"""On Windows, some default encodings are not provided by Python,
	while they are always available as "mbcs" in each locale. Make
	them usable by aliasing to "mbcs" in such a case."""
	if sys.platform == 'win32':
	import _bootlocale, codecs
	enc = _bootlocale.getpreferredencoding(False)
	if enc.startswith('cp'): # "cp***" ?
	try:
	codecs.lookup(enc)
	except LookupError:
	import encodings
	encodings._cache[enc] = encodings._unknown
	encodings.aliases.aliases[enc] = 'mbcs'

	CONFIG_LINE = r'^(?P<key>(\w\|[-_])+)\s=\s(?P<value>.)\s$'

	def venv(known_paths):
	global PREFIXES, ENABLE_USER_SITE

	env = os.environ
	if sys.platform == 'darwin' and '__PYVENV_LAUNCHER__' in env:
	executable = os.environ['__PYVENV_LAUNCHER__']
	else:
	executable = sys.executable
	exe_dir, _ = os.path.split(os.path.abspath(executable))
	site_prefix = os.path.dirname(exe_dir)
	sys._home = None
	conf_basename = 'pyvenv.cfg'
	candidate_confs = [
	conffile for conffile in (
	os.path.join(exe_dir, conf_basename),
	os.path.join(site_prefix, conf_basename)
	)
	if os.path.isfile(conffile)
	]

	if candidate_confs:
	import re
	config_line = re.compile(CONFIG_LINE)
	virtual_conf = candidate_confs[0]
	system_site = "true"
	with open(virtual_conf) as f:
	for line in f:
	line = line.strip()
	m = config_line.match(line)
	if m:
	d = m.groupdict()
	key, value = d['key'].lower(), d['value']
	if key == 'include-system-site-packages':
	system_site = value.lower()
	elif key == 'home':
	sys._home = value

	sys.prefix = sys.exec_prefix = site_prefix

	# Doing this here ensures venv takes precedence over user-site
	addsitepackages(known_paths, [sys.prefix])

	# addsitepackages will process site_prefix again if its in PREFIXES,
	# but that's ok; known_paths will prevent anything being added twice
	if system_site == "true":
	PREFIXES.insert(0, sys.prefix)
	else:
	PREFIXES = [sys.prefix]
	ENABLE_USER_SITE = False

	return known_paths


	def execsitecustomize():
	"""Run custom site specific code, if available."""
	try:
	import sitecustomize
	except ImportError:
	pass
	except Exception as err:
	if os.environ.get("PYTHONVERBOSE"):
	sys.excepthook(*sys.exc_info())
	else:
	sys.stderr.write(
	"Error in sitecustomize; set PYTHONVERBOSE for traceback:\n"
	"%s: %s\n" %
	(err.__class__.__name__, err))


	def execusercustomize():
	"""Run custom user specific code, if available."""
	try:
	import usercustomize
	except ImportError:
	pass
	except Exception as err:
	if os.environ.get("PYTHONVERBOSE"):
	sys.excepthook(*sys.exc_info())
	else:
	sys.stderr.write(
	"Error in usercustomize; set PYTHONVERBOSE for traceback:\n"
	"%s: %s\n" %
	(err.__class__.__name__, err))


	def main():
	"""Add standard site-specific directories to the module search path.

	This function is called automatically when this module is imported,
	unless the python interpreter was started with the -S flag.
	"""
	global ENABLE_USER_SITE

	abs_paths()
	known_paths = removeduppaths()
	known_paths = venv(known_paths)
	if ENABLE_USER_SITE is None:
	ENABLE_USER_SITE = check_enableusersite()
	known_paths = addusersitepackages(known_paths)
	known_paths = addsitepackages(known_paths)
	setquit()
	setcopyright()
	sethelper()
	enablerlcompleter()
	aliasmbcs()
	execsitecustomize()
	if ENABLE_USER_SITE:
	execusercustomize()

	# Prevent edition of sys.path when python was started with -S and
	# site is imported later.
	if not sys.flags.no_site:
	main()

	def _script():
	help = """\
	%s [--user-base] [--user-site]

	Without arguments print some useful information
	With arguments print the value of USER_BASE and/or USER_SITE separated
	by '%s'.

	Exit codes with --user-base or --user-site:
	0 - user site directory is enabled
	1 - user site directory is disabled by user
	2 - uses site directory is disabled by super user
	or for security reasons
	>2 - unknown error
	"""
	args = sys.argv[1:]
	if not args:
	user_base = getuserbase()
	user_site = getusersitepackages()
	print("sys.path = [")
	for dir in sys.path:
	print(" %r," % (dir,))
	print("]")
	print("USER_BASE: %r (%s)" % (user_base,
	"exists" if os.path.isdir(user_base) else "doesn't exist"))
	print("USER_SITE: %r (%s)" % (user_site,
	"exists" if os.path.isdir(user_site) else "doesn't exist"))
	print("ENABLE_USER_SITE: %r" % ENABLE_USER_SITE)
	sys.exit(0)

	buffer = []
	if '--user-base' in args:
	buffer.append(USER_BASE)
	if '--user-site' in args:
	buffer.append(USER_SITE)

	if buffer:
	print(os.pathsep.join(buffer))
	if ENABLE_USER_SITE:
	sys.exit(0)
	elif ENABLE_USER_SITE is False:
	sys.exit(1)
	elif ENABLE_USER_SITE is None:
	sys.exit(2)
	else:
	sys.exit(3)
	else:
	import textwrap
	print(textwrap.dedent(help % (sys.argv[0], os.pathsep)))
	sys.exit(10)

	if __name__ == '__main__':
	_script()