Lib/site.py

   1 """Append module search paths for third-party packages to sys.path.
   2
   3 ****************************************************************
   4 * This module is automatically imported during initialization. *
   5 ****************************************************************
   6
   7 This will append site-specific paths to the module search path.  On
   8 Unix (including Mac OSX), it starts with sys.prefix and
   9 sys.exec_prefix (if different) and appends
  10 lib/python<version>/site-packages as well as lib/site-python.
  11 On other platforms (such as Windows), it tries each of the
  12 prefixes directly, as well as with lib/site-packages appended.  The
  13 resulting directories, if they exist, are appended to sys.path, and
  14 also inspected for path configuration files.
  15
  16 A path configuration file is a file whose name has the form
  17 <package>.pth; its contents are additional directories (one per line)
  18 to be added to sys.path.  Non-existing directories (or
  19 non-directories) are never added to sys.path; no directory is added to
  20 sys.path more than once.  Blank lines and lines beginning with
  21 '#' are skipped. Lines starting with 'import' are executed.
  22
  23 For example, suppose sys.prefix and sys.exec_prefix are set to
  24 /usr/local and there is a directory /usr/local/lib/python2.5/site-packages
  25 with three subdirectories, foo, bar and spam, and two path
  26 configuration files, foo.pth and bar.pth.  Assume foo.pth contains the
  27 following:
  28
  29   # foo package configuration
  30   foo
  31   bar
  32   bletch
  33
  34 and bar.pth contains:
  35
  36   # bar package configuration
  37   bar
  38
  39 Then the following directories are added to sys.path, in this order:
  40
  41   /usr/local/lib/python2.5/site-packages/bar
  42   /usr/local/lib/python2.5/site-packages/foo
  43
  44 Note that bletch is omitted because it doesn't exist; bar precedes foo
  45 because bar.pth comes alphabetically before foo.pth; and spam is
  46 omitted because it is not mentioned in either path configuration file.
  47
  48 After these path manipulations, an attempt is made to import a module
  49 named sitecustomize, which can perform arbitrary additional
  50 site-specific customizations.  If this import fails with an
  51 ImportError exception, it is silently ignored.
  52
  53 """
  54
  55 import sys
  56 import os
  57 import builtins
  58
  59 # Prefixes for site-packages; add additional prefixes like /usr/local here
  60 PREFIXES = [sys.prefix, sys.exec_prefix]
  61 # Enable per user site-packages directory
  62 # set it to False to disable the feature or True to force the feature
  63 ENABLE_USER_SITE = None
  64 # for distutils.commands.install
  65 USER_SITE = None
  66 USER_BASE = None
  67
  68
  69 def makepath(*paths):
  70     dir = os.path.abspath(os.path.join(*paths))
  71     return dir, os.path.normcase(dir)
  72
  73
  74 def abs__file__():
  75     """Set all module' __file__ attribute to an absolute path"""
  76     for m in set(sys.modules.values()):
  77         if hasattr(m, '__loader__'):
  78             continue   # don't mess with a PEP 302-supplied __file__
  79         try:
  80             m.__file__ = os.path.abspath(m.__file__)
  81         except AttributeError:
  82             continue
  83
  84
  85 def removeduppaths():
  86     """ Remove duplicate entries from sys.path along with making them
  87     absolute"""
  88     # This ensures that the initial path provided by the interpreter contains
  89     # only absolute pathnames, even if we're running from the build directory.
  90     L = []
  91     known_paths = set()
  92     for dir in sys.path:
  93         # Filter out duplicate paths (on case-insensitive file systems also
  94         # if they only differ in case); turn relative paths into absolute
  95         # paths.
  96         dir, dircase = makepath(dir)
  97         if not dircase in known_paths:
  98             L.append(dir)
  99             known_paths.add(dircase)
 100     sys.path[:] = L
 101     return known_paths
 102
 103 # XXX This should not be part of site.py, since it is needed even when
 104 # using the -S option for Python.  See http://www.python.org/sf/586680
 105 def addbuilddir():
 106     """Append ./build/lib.<platform> in case we're running in the build dir
 107     (especially for Guido :-)"""
 108     from distutils.util import get_platform
 109     s = "build/lib.%s-%.3s" % (get_platform(), sys.version)
 110     if hasattr(sys, 'gettotalrefcount'):
 111         s += '-pydebug'
 112     s = os.path.join(os.path.dirname(sys.path[-1]), s)
 113     sys.path.append(s)
 114
 115
 116 def _init_pathinfo():
 117     """Return a set containing all existing directory entries from sys.path"""
 118     d = set()
 119     for dir in sys.path:
 120         try:
 121             if os.path.isdir(dir):
 122                 dir, dircase = makepath(dir)
 123                 d.add(dircase)
 124         except TypeError:
 125             continue
 126     return d
 127
 128
 129 def addpackage(sitedir, name, known_paths):
 130     """Process a .pth file within the site-packages directory:
 131        For each line in the file, either combine it with sitedir to a path
 132        and add that to known_paths, or execute it if it starts with 'import '.
 133     """
 134     if known_paths is None:
 135         _init_pathinfo()
 136         reset = 1
 137     else:
 138         reset = 0
 139     fullname = os.path.join(sitedir, name)
 140     try:
 141         f = open(fullname, "rU")
 142     except IOError:
 143         return
 144     with f:
 145         for line in f:
 146             if line.startswith("#"):
 147                 continue
 148             if line.startswith(("import ", "import\t")):
 149                 exec(line)
 150                 continue
 151             line = line.rstrip()
 152             dir, dircase = makepath(sitedir, line)
 153             if not dircase in known_paths and os.path.exists(dir):
 154                 sys.path.append(dir)
 155                 known_paths.add(dircase)
 156     if reset:
 157         known_paths = None
 158     return known_paths
 159
 160
 161 def addsitedir(sitedir, known_paths=None):
 162     """Add 'sitedir' argument to sys.path if missing and handle .pth files in
 163     'sitedir'"""
 164     if known_paths is None:
 165         known_paths = _init_pathinfo()
 166         reset = 1
 167     else:
 168         reset = 0
 169     sitedir, sitedircase = makepath(sitedir)
 170     if not sitedircase in known_paths:
 171         sys.path.append(sitedir)        # Add path component
 172     try:
 173         names = os.listdir(sitedir)
 174     except os.error:
 175         return
 176     names = [name for name in names if name.endswith(".pth")]
 177     for name in sorted(names):
 178         addpackage(sitedir, name, known_paths)
 179     if reset:
 180         known_paths = None
 181     return known_paths
 182
 183
 184 def check_enableusersite():
 185     """Check if user site directory is safe for inclusion
 186
 187     The function tests for the command line flag (including environment var),
 188     process uid/gid equal to effective uid/gid.
 189
 190     None: Disabled for security reasons
 191     False: Disabled by user (command line option)
 192     True: Safe and enabled
 193     """
 194     if sys.flags.no_user_site:
 195         return False
 196
 197     if hasattr(os, "getuid") and hasattr(os, "geteuid"):
 198         # check process uid == effective uid
 199         if os.geteuid() != os.getuid():
 200             return None
 201     if hasattr(os, "getgid") and hasattr(os, "getegid"):
 202         # check process gid == effective gid
 203         if os.getegid() != os.getgid():
 204             return None
 205
 206     return True
 207
 208
 209 def addusersitepackages(known_paths):
 210     """Add a per user site-package to sys.path
 211
 212     Each user has its own python directory with site-packages in the
 213     home directory.
 214
 215     USER_BASE is the root directory for all Python versions
 216
 217     USER_SITE is the user specific site-packages directory
 218
 219     USER_SITE/.. can be used for data.
 220     """
 221     global USER_BASE, USER_SITE, ENABLE_USER_SITE
 222     env_base = os.environ.get("PYTHONUSERBASE", None)
 223
 224     def joinuser(*args):
 225         return os.path.expanduser(os.path.join(*args))
 226
 227     #if sys.platform in ('os2emx', 'riscos'):
 228     #    # Don't know what to put here
 229     #    USER_BASE = ''
 230     #    USER_SITE = ''
 231     if os.name == "nt":
 232         base = os.environ.get("APPDATA") or "~"
 233         USER_BASE = env_base if env_base else joinuser(base, "Python")
 234         USER_SITE = os.path.join(USER_BASE,
 235                                  "Python" + sys.version[0] + sys.version[2],
 236                                  "site-packages")
 237     else:
 238         USER_BASE = env_base if env_base else joinuser("~", ".local")
 239         USER_SITE = os.path.join(USER_BASE, "lib",
 240                                  "python" + sys.version[:3],
 241                                  "site-packages")
 242
 243     if ENABLE_USER_SITE and os.path.isdir(USER_SITE):
 244         addsitedir(USER_SITE, known_paths)
 245     return known_paths
 246
 247
 248 def addsitepackages(known_paths):
 249     """Add site-packages (and possibly site-python) to sys.path"""
 250     sitedirs = []
 251     seen = []
 252
 253     for prefix in PREFIXES:
 254         if not prefix or prefix in seen:
 255             continue
 256         seen.append(prefix)
 257
 258         if sys.platform in ('os2emx', 'riscos'):
 259             sitedirs.append(os.path.join(prefix, "Lib", "site-packages"))
 260         elif os.sep == '/':
 261             sitedirs.append(os.path.join(prefix, "lib",
 262                                         "python" + sys.version[:3],
 263                                         "site-packages"))
 264             sitedirs.append(os.path.join(prefix, "lib", "site-python"))
 265         else:
 266             sitedirs.append(prefix)
 267             sitedirs.append(os.path.join(prefix, "lib", "site-packages"))
 268
 269         if sys.platform == "darwin":
 270             # for framework builds *only* we add the standard Apple
 271             # locations.
 272             if 'Python.framework' in prefix:
 273                 sitedirs.append(
 274                     os.path.expanduser(
 275                         os.path.join("~", "Library", "Python",
 276                                      sys.version[:3], "site-packages")))
 277                 sitedirs.append(
 278                         os.path.join("/Library", "Python",
 279                             sys.version[:3], "site-packages"))
 280
 281     for sitedir in sitedirs:
 282         if os.path.isdir(sitedir):
 283             addsitedir(sitedir, known_paths)
 284
 285     return known_paths
 286
 287
 288 def setBEGINLIBPATH():
 289     """The OS/2 EMX port has optional extension modules that do double duty
 290     as DLLs (and must use the .DLL file extension) for other extensions.
 291     The library search path needs to be amended so these will be found
 292     during module import.  Use BEGINLIBPATH so that these are at the start
 293     of the library search path.
 294
 295     """
 296     dllpath = os.path.join(sys.prefix, "Lib", "lib-dynload")
 297     libpath = os.environ['BEGINLIBPATH'].split(';')
 298     if libpath[-1]:
 299         libpath.append(dllpath)
 300     else:
 301         libpath[-1] = dllpath
 302     os.environ['BEGINLIBPATH'] = ';'.join(libpath)
 303
 304
 305 def setquit():
 306     """Define new built-ins 'quit' and 'exit'.
 307     These are simply strings that display a hint on how to exit.
 308
 309     """
 310     if os.sep == ':':
 311         eof = 'Cmd-Q'
 312     elif os.sep == '\\':
 313         eof = 'Ctrl-Z plus Return'
 314     else:
 315         eof = 'Ctrl-D (i.e. EOF)'
 316
 317     class Quitter(object):
 318         def __init__(self, name):
 319             self.name = name
 320         def __repr__(self):
 321             return 'Use %s() or %s to exit' % (self.name, eof)
 322         def __call__(self, code=None):
 323             # Shells like IDLE catch the SystemExit, but listen when their
 324             # stdin wrapper is closed.
 325             try:
 326                 fd = -1
 327                 if hasattr(sys.stdin, "fileno"):
 328                     fd = sys.stdin.fileno()
 329                 if fd != 0:
 330                     # Don't close stdin if it wraps fd 0
 331                     sys.stdin.close()
 332             except:
 333                 pass
 334             raise SystemExit(code)
 335     builtins.quit = Quitter('quit')
 336     builtins.exit = Quitter('exit')
 337
 338
 339 class _Printer(object):
 340     """interactive prompt objects for printing the license text, a list of
 341     contributors and the copyright notice."""
 342
 343     MAXLINES = 23
 344
 345     def __init__(self, name, data, files=(), dirs=()):
 346         self.__name = name
 347         self.__data = data
 348         self.__files = files
 349         self.__dirs = dirs
 350         self.__lines = None
 351
 352     def __setup(self):
 353         if self.__lines:
 354             return
 355         data = None
 356         for dir in self.__dirs:
 357             for filename in self.__files:
 358                 filename = os.path.join(dir, filename)
 359                 try:
 360                     fp = open(filename, "rU")
 361                     data = fp.read()
 362                     fp.close()
 363                     break
 364                 except IOError:
 365                     pass
 366             if data:
 367                 break
 368         if not data:
 369             data = self.__data
 370         self.__lines = data.split('\n')
 371         self.__linecnt = len(self.__lines)
 372
 373     def __repr__(self):
 374         self.__setup()
 375         if len(self.__lines) <= self.MAXLINES:
 376             return "\n".join(self.__lines)
 377         else:
 378             return "Type %s() to see the full %s text" % ((self.__name,)*2)
 379
 380     def __call__(self):
 381         self.__setup()
 382         prompt = 'Hit Return for more, or q (and Return) to quit: '
 383         lineno = 0
 384         while 1:
 385             try:
 386                 for i in range(lineno, lineno + self.MAXLINES):
 387                     print(self.__lines[i])
 388             except IndexError:
 389                 break
 390             else:
 391                 lineno += self.MAXLINES
 392                 key = None
 393                 while key is None:
 394                     key = input(prompt)
 395                     if key not in ('', 'q'):
 396                         key = None
 397                 if key == 'q':
 398                     break
 399
 400 def setcopyright():
 401     """Set 'copyright' and 'credits' in builtins"""
 402     builtins.copyright = _Printer("copyright", sys.copyright)
 403     if sys.platform[:4] == 'java':
 404         builtins.credits = _Printer(
 405             "credits",
 406             "Jython is maintained by the Jython developers (www.jython.org).")
 407     else:
 408         builtins.credits = _Printer("credits", """\
 409     Thanks to CWI, CNRI, BeOpen.com, Zope Corporation and a cast of thousands
 410     for supporting Python development.  See www.python.org for more information.""")
 411     here = os.path.dirname(os.__file__)
 412     builtins.license = _Printer(
 413         "license", "See http://www.python.org/%.3s/license.html" % sys.version,
 414         ["LICENSE.txt", "LICENSE"],
 415         [os.path.join(here, os.pardir), here, os.curdir])
 416
 417
 418 class _Helper(object):
 419     """Define the built-in 'help'.
 420     This is a wrapper around pydoc.help (with a twist).
 421
 422     """
 423
 424     def __repr__(self):
 425         return "Type help() for interactive help, " \
 426                "or help(object) for help about object."
 427     def __call__(self, *args, **kwds):
 428         import pydoc
 429         return pydoc.help(*args, **kwds)
 430
 431 def sethelper():
 432     builtins.help = _Helper()
 433
 434 def aliasmbcs():
 435     """On Windows, some default encodings are not provided by Python,
 436     while they are always available as "mbcs" in each locale. Make
 437     them usable by aliasing to "mbcs" in such a case."""
 438     if sys.platform == 'win32':
 439         import locale, codecs
 440         enc = locale.getdefaultlocale()[1]
 441         if enc.startswith('cp'):            # "cp***" ?
 442             try:
 443                 codecs.lookup(enc)
 444             except LookupError:
 445                 import encodings
 446                 encodings._cache[enc] = encodings._unknown
 447                 encodings.aliases.aliases[enc] = 'mbcs'
 448
 449 def setencoding():
 450     """Set the string encoding used by the Unicode implementation.  The
 451     default is 'ascii', but if you're willing to experiment, you can
 452     change this."""
 453     encoding = "ascii" # Default value set by _PyUnicode_Init()
 454     if 0:
 455         # Enable to support locale aware default string encodings.
 456         import locale
 457         loc = locale.getdefaultlocale()
 458         if loc[1]:
 459             encoding = loc[1]
 460     if 0:
 461         # Enable to switch off string to Unicode coercion and implicit
 462         # Unicode to string conversion.
 463         encoding = "undefined"
 464     if encoding != "ascii":
 465         # On Non-Unicode builds this will raise an AttributeError...
 466         sys.setdefaultencoding(encoding) # Needs Python Unicode build !
 467
 468
 469 def execsitecustomize():
 470     """Run custom site specific code, if available."""
 471     try:
 472         import sitecustomize
 473     except ImportError:
 474         pass
 475     except Exception as err:
 476         if os.environ.get("PYTHONVERBOSE"):
 477             sys.excepthook(*sys.exc_info())
 478         else:
 479             sys.stderr.write(
 480                 "Error in sitecustomize; set PYTHONVERBOSE for traceback:\n"
 481                 "%s: %s\n" %
 482                 (err.__class__.__name__, err))
 483
 484
 485 def execusercustomize():
 486     """Run custom user specific code, if available."""
 487     try:
 488         import usercustomize
 489     except ImportError:
 490         pass
 491     except Exception as err:
 492         if os.environ.get("PYTHONVERBOSE"):
 493             sys.excepthook(*sys.exc_info())
 494         else:
 495             sys.stderr.write(
 496                 "Error in usercustomize; set PYTHONVERBOSE for traceback:\n"
 497                 "%s: %s\n" %
 498                 (err.__class__.__name__, err))
 499
 500
 501 def main():
 502     global ENABLE_USER_SITE
 503
 504     abs__file__()
 505     known_paths = removeduppaths()
 506     if (os.name == "posix" and sys.path and
 507         os.path.basename(sys.path[-1]) == "Modules"):
 508         addbuilddir()
 509     if ENABLE_USER_SITE is None:
 510         ENABLE_USER_SITE = check_enableusersite()
 511     known_paths = addusersitepackages(known_paths)
 512     known_paths = addsitepackages(known_paths)
 513     if sys.platform == 'os2emx':
 514         setBEGINLIBPATH()
 515     setquit()
 516     setcopyright()
 517     sethelper()
 518     aliasmbcs()
 519     setencoding()
 520     execsitecustomize()
 521     if ENABLE_USER_SITE:
 522         execusercustomize()
 523     # Remove sys.setdefaultencoding() so that users cannot change the
 524     # encoding after initialization.  The test for presence is needed when
 525     # this module is run as a script, because this code is executed twice.
 526     if hasattr(sys, "setdefaultencoding"):
 527         del sys.setdefaultencoding
 528
 529 main()
 530
 531 def _script():
 532     help = """\
 533     %s [--user-base] [--user-site]
 534
 535     Without arguments print some useful information
 536     With arguments print the value of USER_BASE and/or USER_SITE separated
 537     by '%s'.
 538
 539     Exit codes with --user-base or --user-site:
 540       0 - user site directory is enabled
 541       1 - user site directory is disabled by user
 542       2 - uses site directory is disabled by super user
 543           or for security reasons
 544      >2 - unknown error
 545     """
 546     args = sys.argv[1:]
 547     if not args:
 548         print("sys.path = [")
 549         for dir in sys.path:
 550             print("    %r," % (dir,))
 551         print("]")
 552         print("USER_BASE: %r (%s)" % (USER_BASE,
 553             "exists" if os.path.isdir(USER_BASE) else "doesn't exist"))
 554         print("USER_SITE: %r (%s)" % (USER_SITE,
 555             "exists" if os.path.isdir(USER_SITE) else "doesn't exist"))
 556         print("ENABLE_USER_SITE: %r" %  ENABLE_USER_SITE)
 557         sys.exit(0)
 558
 559     buffer = []
 560     if '--user-base' in args:
 561         buffer.append(USER_BASE)
 562     if '--user-site' in args:
 563         buffer.append(USER_SITE)
 564
 565     if buffer:
 566         print(os.pathsep.join(buffer))
 567         if ENABLE_USER_SITE:
 568             sys.exit(0)
 569         elif ENABLE_USER_SITE is False:
 570             sys.exit(1)
 571         elif ENABLE_USER_SITE is None:
 572             sys.exit(2)
 573         else:
 574             sys.exit(3)
 575     else:
 576         import textwrap
 577         print(textwrap.dedent(help % (sys.argv[0], os.pathsep)))
 578         sys.exit(10)
 579
 580 if __name__ == '__main__':
 581     _script()