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cpython/Lib/site.py

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"""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 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.
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 and site-python (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.
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.
"""
import sys
import os
import re
import builtins
# 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) !=
'_frozen_importlib'):
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:
_init_pathinfo()
reset = 1
else:
reset = 0
fullname = os.path.join(sitedir, name)
try:
f = open(fullname, "r")
except IOError:
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
(and possibly site-python).
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"))
sitepackages.append(os.path.join(prefix, "lib", "site-python"))
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 (and possibly site-python) 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)'
class Quitter(object):
def __init__(self, name):
self.name = name
def __repr__(self):
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.
try:
fd = -1
if hasattr(sys.stdin, "fileno"):
fd = sys.stdin.fileno()
if fd != 0:
# Don't close stdin if it wraps fd 0
sys.stdin.close()
except:
pass
raise SystemExit(code)
builtins.quit = Quitter('quit')
builtins.exit = Quitter('exit')
class _Printer(object):
"""interactive prompt objects for printing the license text, a list of
contributors and the copyright notice."""
MAXLINES = 23
def __init__(self, name, data, files=(), dirs=()):
self.__name = name
self.__data = data
self.__files = files
self.__dirs = dirs
self.__lines = None
def __setup(self):
if self.__lines:
return
data = None
for dir in self.__dirs:
for filename in self.__files:
filename = os.path.join(dir, filename)
try:
fp = open(filename, "r")
data = fp.read()
fp.close()
break
except IOError:
pass
if data:
break
if not data:
data = self.__data
self.__lines = data.split('\n')
self.__linecnt = len(self.__lines)
def __repr__(self):
self.__setup()
if len(self.__lines) <= self.MAXLINES:
return "\n".join(self.__lines)
else:
return "Type %s() to see the full %s text" % ((self.__name,)*2)
def __call__(self):
self.__setup()
prompt = 'Hit Return for more, or q (and Return) to quit: '
lineno = 0
while 1:
try:
for i in range(lineno, lineno + self.MAXLINES):
print(self.__lines[i])
except IndexError:
break
else:
lineno += self.MAXLINES
key = None
while key is None:
key = input(prompt)
if key not in ('', 'q'):
key = None
if key == 'q':
break
def setcopyright():
"""Set 'copyright' and 'credits' in builtins"""
builtins.copyright = _Printer("copyright", sys.copyright)
if sys.platform[:4] == 'java':
builtins.credits = _Printer(
"credits",
"Jython is maintained by the Jython developers (www.jython.org).")
else:
builtins.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__)
builtins.license = _Printer(
"license", "See http://www.python.org/%.3s/license.html" % sys.version,
["LICENSE.txt", "LICENSE"],
[os.path.join(here, os.pardir), here, os.curdir])
class _Helper(object):
"""Define the builtin 'help'.
This is a wrapper around pydoc.help (with a twist).
"""
def __repr__(self):
return "Type help() for interactive help, " \
"or help(object) for help about object."
def __call__(self, *args, **kwds):
import pydoc
return pydoc.help(*args, **kwds)
def sethelper():
builtins.help = _Helper()
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 locale, codecs
enc = locale.getdefaultlocale()[1]
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 = re.compile(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:
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()
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:
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()
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