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 In earlier versions of Python (up to 1.5a3), scripts or modules that
   8 needed to use site-specific modules would place ``import site''
   9 somewhere near the top of their code.  Because of the automatic
  10 import, this is no longer necessary (but code that does it still
  11 works).
  12
  13 This will append site-specific paths to to the module search path.  On
  14 Unix, it starts with sys.prefix and sys.exec_prefix (if different) and
  15 appends lib/python<version>/site-packages as well as lib/site-python.
  16 On other platforms (mainly Mac and Windows), it uses just sys.prefix
  17 (and sys.exec_prefix, if different, but this is unlikely).  The
  18 resulting directories, if they exist, are appended to sys.path, and
  19 also inspected for path configuration files.
  20
  21 A path configuration file is a file whose name has the form
  22 <package>.pth; its contents are additional directories (one per line)
  23 to be added to sys.path.  Non-existing directories (or
  24 non-directories) are never added to sys.path; no directory is added to
  25 sys.path more than once.  Blank lines and lines beginning with
  26 '#' are skipped. Lines starting with 'import' are executed.
  27
  28 For example, suppose sys.prefix and sys.exec_prefix are set to
  29 /usr/local and there is a directory /usr/local/lib/python1.5/site-packages
  30 with three subdirectories, foo, bar and spam, and two path
  31 configuration files, foo.pth and bar.pth.  Assume foo.pth contains the
  32 following:
  33
  34   # foo package configuration
  35   foo
  36   bar
  37   bletch
  38
  39 and bar.pth contains:
  40
  41   # bar package configuration
  42   bar
  43
  44 Then the following directories are added to sys.path, in this order:
  45
  46   /usr/local/lib/python1.5/site-packages/bar
  47   /usr/local/lib/python1.5/site-packages/foo
  48
  49 Note that bletch is omitted because it doesn't exist; bar precedes foo
  50 because bar.pth comes alphabetically before foo.pth; and spam is
  51 omitted because it is not mentioned in either path configuration file.
  52
  53 After these path manipulations, an attempt is made to import a module
  54 named sitecustomize, which can perform arbitrary additional
  55 site-specific customizations.  If this import fails with an
  56 ImportError exception, it is silently ignored.
  57
  58 """
  59
  60 import sys, os
  61
  62
  63 def makepath(*paths):
  64     dir = os.path.abspath(os.path.join(*paths))
  65     return dir, os.path.normcase(dir)
  66
  67 for m in sys.modules.values():
  68     if hasattr(m, "__file__") and m.__file__:
  69         m.__file__ = os.path.abspath(m.__file__)
  70 del m
  71
  72 # This ensures that the initial path provided by the interpreter contains
  73 # only absolute pathnames, even if we're running from the build directory.
  74 L = []
  75 _dirs_in_sys_path = {}
  76 dir = dircase = None  # sys.path may be empty at this point
  77 for dir in sys.path:
  78     # Filter out duplicate paths (on case-insensitive file systems also
  79     # if they only differ in case); turn relative paths into absolute
  80     # paths.
  81     dir, dircase = makepath(dir)
  82     if not dircase in _dirs_in_sys_path:
  83         L.append(dir)
  84         _dirs_in_sys_path[dircase] = 1
  85 sys.path[:] = L
  86 del dir, dircase, L
  87
  88 # Append ./build/lib.<platform> in case we're running in the build dir
  89 # (especially for Guido :-)
  90 # XXX This should not be part of site.py, since it is needed even when
  91 # using the -S option for Python.  See http://www.python.org/sf/586680
  92 if (os.name == "posix" and sys.path and
  93     os.path.basename(sys.path[-1]) == "Modules"):
  94     from distutils.util import get_platform
  95     s = "build/lib.%s-%.3s" % (get_platform(), sys.version)
  96     s = os.path.join(os.path.dirname(sys.path[-1]), s)
  97     sys.path.append(s)
  98     del get_platform, s
  99
 100 def _init_pathinfo():
 101     global _dirs_in_sys_path
 102     _dirs_in_sys_path = d = {}
 103     for dir in sys.path:
 104         if dir and not os.path.isdir(dir):
 105             continue
 106         dir, dircase = makepath(dir)
 107         d[dircase] = 1
 108
 109 def addsitedir(sitedir):
 110     global _dirs_in_sys_path
 111     if _dirs_in_sys_path is None:
 112         _init_pathinfo()
 113         reset = 1
 114     else:
 115         reset = 0
 116     sitedir, sitedircase = makepath(sitedir)
 117     if not sitedircase in _dirs_in_sys_path:
 118         sys.path.append(sitedir)        # Add path component
 119     try:
 120         names = os.listdir(sitedir)
 121     except os.error:
 122         return
 123     names.sort()
 124     for name in names:
 125         if name[-4:] == os.extsep + "pth":
 126             addpackage(sitedir, name)
 127     if reset:
 128         _dirs_in_sys_path = None
 129
 130 def addpackage(sitedir, name):
 131     global _dirs_in_sys_path
 132     if _dirs_in_sys_path is None:
 133         _init_pathinfo()
 134         reset = 1
 135     else:
 136         reset = 0
 137     fullname = os.path.join(sitedir, name)
 138     try:
 139         f = open(fullname)
 140     except IOError:
 141         return
 142     while 1:
 143         dir = f.readline()
 144         if not dir:
 145             break
 146         if dir[0] == '#':
 147             continue
 148         if dir.startswith("import"):
 149             exec dir
 150             continue
 151         if dir[-1] == '\n':
 152             dir = dir[:-1]
 153         dir, dircase = makepath(sitedir, dir)
 154         if not dircase in _dirs_in_sys_path and os.path.exists(dir):
 155             sys.path.append(dir)
 156             _dirs_in_sys_path[dircase] = 1
 157     if reset:
 158         _dirs_in_sys_path = None
 159
 160 prefixes = [sys.prefix]
 161 if sys.exec_prefix != sys.prefix:
 162     prefixes.append(sys.exec_prefix)
 163 for prefix in prefixes:
 164     if prefix:
 165         if sys.platform == 'os2emx':
 166             sitedirs = [os.path.join(prefix, "Lib", "site-packages")]
 167         elif os.sep == '/':
 168             sitedirs = [os.path.join(prefix,
 169                                      "lib",
 170                                      "python" + sys.version[:3],
 171                                      "site-packages"),
 172                         os.path.join(prefix, "lib", "site-python")]
 173         else:
 174             sitedirs = [prefix, os.path.join(prefix, "lib", "site-packages")]
 175         if sys.platform == 'darwin':
 176             # for framework builds *only* we add the standard Apple
 177             # locations. Currently only per-user, but /Library and
 178             # /Network/Library could be added too
 179             if 'Python.framework' in prefix:
 180                 home = os.environ['HOME']
 181                 if home:
 182                     sitedirs.append(
 183                         os.path.join(home,
 184                                      'Library',
 185                                      'Python',
 186                                      sys.version[:3],
 187                                      'site-packages'))
 188         for sitedir in sitedirs:
 189             if os.path.isdir(sitedir):
 190                 addsitedir(sitedir)
 191 del prefix, sitedir
 192
 193 _dirs_in_sys_path = None
 194
 195
 196 # Define new built-ins 'quit' and 'exit'.
 197 # These are simply strings that display a hint on how to exit.
 198 if os.sep == ':':
 199     exit = 'Use Cmd-Q to quit.'
 200 elif os.sep == '\\':
 201     exit = 'Use Ctrl-Z plus Return to exit.'
 202 else:
 203     exit = 'Use Ctrl-D (i.e. EOF) to exit.'
 204 import __builtin__
 205 __builtin__.quit = __builtin__.exit = exit
 206 del exit
 207
 208 # interactive prompt objects for printing the license text, a list of
 209 # contributors and the copyright notice.
 210 class _Printer:
 211     MAXLINES = 23
 212
 213     def __init__(self, name, data, files=(), dirs=()):
 214         self.__name = name
 215         self.__data = data
 216         self.__files = files
 217         self.__dirs = dirs
 218         self.__lines = None
 219
 220     def __setup(self):
 221         if self.__lines:
 222             return
 223         data = None
 224         for dir in self.__dirs:
 225             for file in self.__files:
 226                 file = os.path.join(dir, file)
 227                 try:
 228                     fp = open(file)
 229                     data = fp.read()
 230                     fp.close()
 231                     break
 232                 except IOError:
 233                     pass
 234             if data:
 235                 break
 236         if not data:
 237             data = self.__data
 238         self.__lines = data.split('\n')
 239         self.__linecnt = len(self.__lines)
 240
 241     def __repr__(self):
 242         self.__setup()
 243         if len(self.__lines) <= self.MAXLINES:
 244             return "\n".join(self.__lines)
 245         else:
 246             return "Type %s() to see the full %s text" % ((self.__name,)*2)
 247
 248     def __call__(self):
 249         self.__setup()
 250         prompt = 'Hit Return for more, or q (and Return) to quit: '
 251         lineno = 0
 252         while 1:
 253             try:
 254                 for i in range(lineno, lineno + self.MAXLINES):
 255                     print self.__lines[i]
 256             except IndexError:
 257                 break
 258             else:
 259                 lineno += self.MAXLINES
 260                 key = None
 261                 while key is None:
 262                     key = raw_input(prompt)
 263                     if key not in ('', 'q'):
 264                         key = None
 265                 if key == 'q':
 266                     break
 267
 268 __builtin__.copyright = _Printer("copyright", sys.copyright)
 269 if sys.platform[:4] == 'java':
 270     __builtin__.credits = _Printer(
 271         "credits",
 272         "Jython is maintained by the Jython developers (www.jython.org).")
 273 else:
 274     __builtin__.credits = _Printer("credits", """\
 275 Thanks to CWI, CNRI, BeOpen.com, Zope Corporation and a cast of thousands
 276 for supporting Python development.  See www.python.org for more information.""")
 277 here = os.path.dirname(os.__file__)
 278 __builtin__.license = _Printer(
 279     "license", "See http://www.python.org/%.3s/license.html" % sys.version,
 280     ["LICENSE.txt", "LICENSE"],
 281     [os.path.join(here, os.pardir), here, os.curdir])
 282
 283
 284 # Define new built-in 'help'.
 285 # This is a wrapper around pydoc.help (with a twist).
 286
 287 class _Helper:
 288     def __repr__(self):
 289         return "Type help() for interactive help, " \
 290                "or help(object) for help about object."
 291     def __call__(self, *args, **kwds):
 292         import pydoc
 293         return pydoc.help(*args, **kwds)
 294
 295 __builtin__.help = _Helper()
 296
 297
 298 # On Windows, some default encodings are not provided
 299 # by Python (e.g. "cp932" in Japanese locale), while they
 300 # are always available as "mbcs" in each locale.
 301 # Make them usable by aliasing to "mbcs" in such a case.
 302
 303 if sys.platform == 'win32':
 304     import locale, codecs
 305     enc = locale.getdefaultlocale()[1]
 306     if enc.startswith('cp'):            # "cp***" ?
 307         try:
 308             codecs.lookup(enc)
 309         except LookupError:
 310             import encodings
 311             encodings._cache[enc] = encodings._unknown
 312             encodings.aliases.aliases[enc] = 'mbcs'
 313
 314 # Set the string encoding used by the Unicode implementation.  The
 315 # default is 'ascii', but if you're willing to experiment, you can
 316 # change this.
 317
 318 encoding = "ascii" # Default value set by _PyUnicode_Init()
 319
 320 if 0:
 321     # Enable to support locale aware default string encodings.
 322     import locale
 323     loc = locale.getdefaultlocale()
 324     if loc[1]:
 325         encoding = loc[1]
 326
 327 if 0:
 328     # Enable to switch off string to Unicode coercion and implicit
 329     # Unicode to string conversion.
 330     encoding = "undefined"
 331
 332 if encoding != "ascii":
 333     # On Non-Unicode builds this will raise an AttributeError...
 334     sys.setdefaultencoding(encoding) # Needs Python Unicode build !
 335
 336 #
 337 # Run custom site specific code, if available.
 338 #
 339 try:
 340     import sitecustomize
 341 except ImportError:
 342     pass
 343
 344 #
 345 # Remove sys.setdefaultencoding() so that users cannot change the
 346 # encoding after initialization.  The test for presence is needed when
 347 # this module is run as a script, because this code is executed twice.
 348 #
 349 if hasattr(sys, "setdefaultencoding"):
 350     del sys.setdefaultencoding
 351
 352 def _test():
 353     print "sys.path = ["
 354     for dir in sys.path:
 355         print "    %s," % `dir`
 356     print "]"
 357
 358 if __name__ == '__main__':
 359     _test()