cpython/Lib/site.py

303 lines
9.3 KiB
Python

"""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
works).
This will append site-specific paths to to the module search path. On
Unix, 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 (mainly Mac and Windows), it uses just sys.prefix
\(and sys.exec_prefix, if different, but this is unlikely). 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
\code{#} are skipped. Lines starting with \code{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/python1.5/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/python1.5/site-packages/bar
/usr/local/lib/python1.5/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, os
if os.sep==".":
endsep = "/"
else:
endsep = "."
def makepath(*paths):
dir = os.path.abspath(os.path.join(*paths))
return dir, os.path.normcase(dir)
for m in sys.modules.values():
if hasattr(m, "__file__") and m.__file__:
m.__file__ = os.path.abspath(m.__file__)
del m
# This ensures that the initial path provided by the interpreter contains
# only absolute pathnames, even if we're running from the build directory.
L = []
dirs_in_sys_path = {}
for dir in sys.path:
# Filter out paths that don't exist, but leave in the empty string
# since it's a special case.
if dir and not os.path.isdir(dir):
continue
dir, dircase = makepath(dir)
if not dirs_in_sys_path.has_key(dircase):
L.append(dir)
dirs_in_sys_path[dircase] = 1
sys.path[:] = L
del dir, L
# Append ./build/lib.<platform> in case we're running in the build dir
# (especially for Guido :-)
if os.name == "posix" and os.path.basename(sys.path[-1]) == "Modules":
from distutils.util import get_platform
s = "build/lib.%s-%.3s" % (get_platform(), sys.version)
s = os.path.join(os.path.dirname(sys.path[-1]), s)
sys.path.append(s)
del get_platform, s
def addsitedir(sitedir):
sitedir, sitedircase = makepath(sitedir)
if not dirs_in_sys_path.has_key(sitedircase):
sys.path.append(sitedir) # Add path component
try:
names = os.listdir(sitedir)
except os.error:
return
names.sort()
for name in names:
if name[-4:] == endsep + "pth":
addpackage(sitedir, name)
def addpackage(sitedir, name):
fullname = os.path.join(sitedir, name)
try:
f = open(fullname)
except IOError:
return
while 1:
dir = f.readline()
if not dir:
break
if dir[0] == '#':
continue
if dir.startswith("import"):
exec dir
continue
if dir[-1] == '\n':
dir = dir[:-1]
dir, dircase = makepath(sitedir, dir)
if not dirs_in_sys_path.has_key(dircase) and os.path.exists(dir):
sys.path.append(dir)
dirs_in_sys_path[dircase] = 1
prefixes = [sys.prefix]
if sys.exec_prefix != sys.prefix:
prefixes.append(sys.exec_prefix)
for prefix in prefixes:
if prefix:
if os.sep == '/':
sitedirs = [os.path.join(prefix,
"lib",
"python" + sys.version[:3],
"site-packages"),
os.path.join(prefix, "lib", "site-python")]
else:
sitedirs = [prefix, os.path.join(prefix, "lib", "site-packages")]
for sitedir in sitedirs:
if os.path.isdir(sitedir):
addsitedir(sitedir)
del dirs_in_sys_path
# Define new built-ins 'quit' and 'exit'.
# These are simply strings that display a hint on how to exit.
if os.sep == ':':
exit = 'Use Cmd-Q to quit.'
elif os.sep == '\\':
exit = 'Use Ctrl-Z plus Return to exit.'
else:
exit = 'Use Ctrl-D (i.e. EOF) to exit.'
import __builtin__
__builtin__.quit = __builtin__.exit = exit
del exit
# interactive prompt objects for printing the license text, a list of
# contributors and the copyright notice.
class _Printer:
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 file in self.__files:
file = os.path.join(dir, file)
try:
fp = open(file)
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 = raw_input(prompt)
if key not in ('', 'q'):
key = None
if key == 'q':
break
__builtin__.copyright = _Printer("copyright", sys.copyright)
if sys.platform[:4] == 'java':
__builtin__.credits = _Printer(
"credits",
"Jython is maintained by the Jython developers (www.jython.org).")
else:
__builtin__.credits = _Printer("credits", """\
Thanks to CWI, CNRI, BeOpen.com, Digital Creations 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 http://www.pythonlabs.com/products/python2.0/license.html",
["LICENSE.txt", "LICENSE"],
[os.path.join(here, os.pardir), here, os.curdir])
# Define new built-in 'help'.
# This is a wrapper around pydoc.help (with a twist).
class _Helper:
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)
__builtin__.help = _Helper()
# Set the string encoding used by the Unicode implementation. The
# default is 'ascii', but if you're willing to experiment, you can
# change this.
encoding = "ascii" # Default value set by _PyUnicode_Init()
if 0:
# Enable to support locale aware default string encodings.
import locale
loc = locale.getdefaultlocale()
if loc[1]:
encoding = loc[1]
if 0:
# Enable to switch off string to Unicode coercion and implicit
# Unicode to string conversion.
encoding = "undefined"
if encoding != "ascii":
sys.setdefaultencoding(encoding)
#
# Run custom site specific code, if available.
#
try:
import sitecustomize
except ImportError:
pass
#
# Remove sys.setdefaultencoding() so that users cannot change the
# encoding after initialization. The test for presence is needed when
# this module is run as a script, because this code is executed twice.
#
if hasattr(sys, "setdefaultencoding"):
del sys.setdefaultencoding
def _test():
print "sys.path = ["
for dir in sys.path:
print " %s," % `dir`
print "]"
if __name__ == '__main__':
_test()