"""Append module search paths for third-party packages to sys.path.
****************************************************************
* This module is automatically imported during initialization. *
****************************************************************
In earlier versions of Python (up to 1.5a3), scripts or modules that
needed to use site-specific modules would place ``import site''
somewhere near the top of their code. Because of the automatic
import, this is no longer necessary (but code that does it still
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 as well as lib/site-python.
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.
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
# foo package configuration
# bar package configuration
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.
After these path manipulations, 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.
# 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
# for distutils.commands.install
# These values are initialized by the getuserbase() and getusersitepackages()
# functions, through the main() function when Python starts.
dir = os.path.join(*paths)
dir = os.path.abspath(dir)
return dir, os.path.normcase(dir)
"""Set all module' __file__ attribute to an absolute path"""
for m in sys.modules.values():
if hasattr(m, '__loader__'):
continue # don't mess with a PEP 302-supplied __file__
m.__file__ = os.path.abspath(m.__file__)
except (AttributeError, OSError):
""" Remove duplicate entries from sys.path along with making them
# This ensures that the initial path provided by the interpreter contains
# only absolute pathnames, even if we're running from the build directory.
# Filter out duplicate paths (on case-insensitive file systems also
# if they only differ in case); turn relative paths into absolute
dir, dircase = makepath(dir)
if not dircase in known_paths:
"""Return a set containing all existing directory entries from sys.path"""
dir, dircase = makepath(dir)
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 '.
fullname = os.path.join(sitedir, name)
for n, line in enumerate(f):
if line.startswith(("import ", "import\t")):
dir, dircase = makepath(sitedir, line)
if not dircase in known_paths and os.path.exists(dir):
print >>sys.stderr, "Error processing line {:d} of {}:\n".format(
for record in traceback.format_exception(*sys.exc_info()):
for line in record.splitlines():
print >>sys.stderr, ' '+line
print >>sys.stderr, "\nRemainder of file ignored"
def addsitedir(sitedir, known_paths=None):
"""Add 'sitedir' argument to sys.path if missing and handle .pth files in
known_paths = _init_pathinfo()
sitedir, sitedircase = makepath(sitedir)
if not sitedircase in known_paths:
sys.path.append(sitedir) # Add path component
names = os.listdir(sitedir)
dotpth = os.extsep + "pth"
names = [name for name in names if name.endswith(dotpth)]
for name in sorted(names):
addpackage(sitedir, name, 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)
if sys.flags.no_user_site:
if hasattr(os, "getuid") and hasattr(os, "geteuid"):
# check process uid == effective uid
if os.geteuid() != os.getuid():
if hasattr(os, "getgid") and hasattr(os, "getegid"):
# check process gid == effective gid
if os.getegid() != os.getgid():
"""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
if USER_BASE is not None:
from sysconfig import get_config_var
USER_BASE = get_config_var('userbase')
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.
user_base = getuserbase() # this will also set USER_BASE
if USER_SITE is not None:
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')
USER_SITE = get_path('purelib', '%s_user' % os.name)
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
# 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)
"""Returns a list containing all global site-packages directories
(and possibly site-python).
For each directory present in the global ``PREFIXES``, this function
will find its `site-packages` subdirectory depending on the system
environment, and will return a list of full paths.
if not prefix or prefix in seen:
if sys.platform in ('os2emx', 'riscos'):
sitepackages.append(os.path.join(prefix, "Lib", "site-packages"))
sitepackages.append(os.path.join(prefix, "lib64",
"python" + sys.version[:3],
sitepackages.append(os.path.join(prefix, "lib",
"python" + sys.version[:3],
sitepackages.append(os.path.join(prefix, "lib", "site-python"))
sitepackages.append(prefix)
sitepackages.append(os.path.join(prefix, "lib64", "site-packages"))
sitepackages.append(os.path.join(prefix, "lib", "site-packages"))
def addsitepackages(known_paths):
"""Add site-packages (and possibly site-python) to sys.path"""
for sitedir in getsitepackages():
if os.path.isdir(sitedir):
addsitedir(sitedir, known_paths)
"""The OS/2 EMX port has optional extension modules that do double duty
as DLLs (and must use the .DLL file extension) for other extensions.
The library search path needs to be amended so these will be found
during module import. Use BEGINLIBPATH so that these are at the start
of the library search path.
dllpath = os.path.join(sys.prefix, "Lib", "lib-dynload")
libpath = os.environ['BEGINLIBPATH'].split(';')
os.environ['BEGINLIBPATH'] = ';'.join(libpath)
"""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.
eof = 'Ctrl-Z plus Return'
eof = 'Ctrl-D (i.e. EOF)'
def __init__(self, name):
return 'Use %s() or %s to exit' % (self.name, eof)
def __call__(self, code=None):
# Shells like IDLE catch the SystemExit, but listen when their
# stdin wrapper is closed.
__builtin__.quit = Quitter('quit')
__builtin__.exit = Quitter('exit')
"""interactive prompt objects for printing the license text, a list of
contributors and the copyright notice."""
def __init__(self, name, data, files=(), dirs=()):
for filename in self.__files:
filename = os.path.join(dir, filename)
fp = file(filename, "rU")
self.__lines = data.split('\n')
self.__linecnt = len(self.__lines)
if len(self.__lines) <= self.MAXLINES:
return "\n".join(self.__lines)
return "Type %s() to see the full %s text" % ((self.__name,)*2)
prompt = 'Hit Return for more, or q (and Return) to quit: '
for i in range(lineno, lineno + self.MAXLINES):
"""Set 'copyright' and 'credits' in __builtin__"""
__builtin__.copyright = _Printer("copyright", sys.copyright)
if sys.platform[:4] == 'java':
__builtin__.credits = _Printer(
"Jython is maintained by the Jython developers (www.jython.org).")
__builtin__.credits = _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.""")
here = os.path.dirname(os.__file__)
__builtin__.license = _Printer(
"license", "See https://www.python.org/psf/license/",
["LICENSE.txt", "LICENSE"],
[os.path.join(here, os.pardir), here, os.curdir])
"""Define the builtin 'help'.
This is a wrapper around pydoc.help (with a twist).
return "Type help() for interactive help, " \
"or help(object) for help about object."
def __call__(self, *args, **kwds):
return pydoc.help(*args, **kwds)
__builtin__.help = _Helper()
"""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':
enc = locale.getdefaultlocale()[1]
if enc.startswith('cp'): # "cp***" ?
encodings._cache[enc] = encodings._unknown
encodings.aliases.aliases[enc] = 'mbcs'
"""Set the string encoding used by the Unicode implementation. The
default is 'ascii', but if you're willing to experiment, you can
encoding = "ascii" # Default value set by _PyUnicode_Init()
# Enable to support locale aware default string encodings.
loc = locale.getdefaultlocale()
# Enable to switch off string to Unicode coercion and implicit
# Unicode to string conversion.
# On Non-Unicode builds this will raise an AttributeError...
sys.setdefaultencoding(encoding) # Needs Python Unicode build !
"""Run custom site specific code, if available."""
sys.excepthook(*sys.exc_info())