source: trunk/essentials/dev-lang/python/Lib/site.py

Last change on this file was 3401, checked in by bird, 18 years ago

addbuilddir() for OS/2. Adding 'os2knix'.

File size: 14.2 KB
Line 
1"""Append module search paths for third-party packages to sys.path.
2
3****************************************************************
4* This module is automatically imported during initialization. *
5****************************************************************
6
7In earlier versions of Python (up to 1.5a3), scripts or modules that
8needed to use site-specific modules would place ``import site''
9somewhere near the top of their code. Because of the automatic
10import, this is no longer necessary (but code that does it still
11works).
12
13This will append site-specific paths to the module search path. On
14Unix (including Mac OSX), it starts with sys.prefix and
15sys.exec_prefix (if different) and appends
16lib/python<version>/site-packages as well as lib/site-python.
17On other platforms (such as Windows), it tries each of the
18prefixes directly, as well as with lib/site-packages appended. The
19resulting directories, if they exist, are appended to sys.path, and
20also inspected for path configuration files.
21
22A path configuration file is a file whose name has the form
23<package>.pth; its contents are additional directories (one per line)
24to be added to sys.path. Non-existing directories (or
25non-directories) are never added to sys.path; no directory is added to
26sys.path more than once. Blank lines and lines beginning with
27'#' are skipped. Lines starting with 'import' are executed.
28
29For example, suppose sys.prefix and sys.exec_prefix are set to
30/usr/local and there is a directory /usr/local/lib/python2.5/site-packages
31with three subdirectories, foo, bar and spam, and two path
32configuration files, foo.pth and bar.pth. Assume foo.pth contains the
33following:
34
35 # foo package configuration
36 foo
37 bar
38 bletch
39
40and bar.pth contains:
41
42 # bar package configuration
43 bar
44
45Then the following directories are added to sys.path, in this order:
46
47 /usr/local/lib/python2.5/site-packages/bar
48 /usr/local/lib/python2.5/site-packages/foo
49
50Note that bletch is omitted because it doesn't exist; bar precedes foo
51because bar.pth comes alphabetically before foo.pth; and spam is
52omitted because it is not mentioned in either path configuration file.
53
54After these path manipulations, an attempt is made to import a module
55named sitecustomize, which can perform arbitrary additional
56site-specific customizations. If this import fails with an
57ImportError exception, it is silently ignored.
58
59"""
60
61import sys
62import os
63import __builtin__
64
65
66def makepath(*paths):
67 dir = os.path.abspath(os.path.join(*paths))
68 return dir, os.path.normcase(dir)
69
70def abs__file__():
71 """Set all module' __file__ attribute to an absolute path"""
72 for m in sys.modules.values():
73 if hasattr(m, '__loader__'):
74 continue # don't mess with a PEP 302-supplied __file__
75 try:
76 m.__file__ = os.path.abspath(m.__file__)
77 except AttributeError:
78 continue
79
80def removeduppaths():
81 """ Remove duplicate entries from sys.path along with making them
82 absolute"""
83 # This ensures that the initial path provided by the interpreter contains
84 # only absolute pathnames, even if we're running from the build directory.
85 L = []
86 known_paths = set()
87 for dir in sys.path:
88 # Filter out duplicate paths (on case-insensitive file systems also
89 # if they only differ in case); turn relative paths into absolute
90 # paths.
91 dir, dircase = makepath(dir)
92 if not dircase in known_paths:
93 L.append(dir)
94 known_paths.add(dircase)
95 sys.path[:] = L
96 return known_paths
97
98# XXX This should not be part of site.py, since it is needed even when
99# using the -S option for Python. See http://www.python.org/sf/586680
100def addbuilddir():
101 """Append ./build/lib.<platform> in case we're running in the build dir
102 (especially for Guido :-)"""
103 from distutils.util import get_platform
104 s = "build/lib.%s-%.3s" % (get_platform(), sys.version)
105 s = os.path.join(os.path.dirname(sys.path[-1]), s)
106 sys.path.append(s)
107
108def _init_pathinfo():
109 """Return a set containing all existing directory entries from sys.path"""
110 d = set()
111 for dir in sys.path:
112 try:
113 if os.path.isdir(dir):
114 dir, dircase = makepath(dir)
115 d.add(dircase)
116 except TypeError:
117 continue
118 return d
119
120def addpackage(sitedir, name, known_paths):
121 """Add a new path to known_paths by combining sitedir and 'name' or execute
122 sitedir if it starts with 'import'"""
123 if known_paths is None:
124 _init_pathinfo()
125 reset = 1
126 else:
127 reset = 0
128 fullname = os.path.join(sitedir, name)
129 try:
130 f = open(fullname, "rU")
131 except IOError:
132 return
133 try:
134 for line in f:
135 if line.startswith("#"):
136 continue
137 if line.startswith("import"):
138 exec line
139 continue
140 line = line.rstrip()
141 dir, dircase = makepath(sitedir, line)
142 if not dircase in known_paths and os.path.exists(dir):
143 sys.path.append(dir)
144 known_paths.add(dircase)
145 finally:
146 f.close()
147 if reset:
148 known_paths = None
149 return known_paths
150
151def addsitedir(sitedir, known_paths=None):
152 """Add 'sitedir' argument to sys.path if missing and handle .pth files in
153 'sitedir'"""
154 if known_paths is None:
155 known_paths = _init_pathinfo()
156 reset = 1
157 else:
158 reset = 0
159 sitedir, sitedircase = makepath(sitedir)
160 if not sitedircase in known_paths:
161 sys.path.append(sitedir) # Add path component
162 try:
163 names = os.listdir(sitedir)
164 except os.error:
165 return
166 names.sort()
167 for name in names:
168 if name.endswith(os.extsep + "pth"):
169 addpackage(sitedir, name, known_paths)
170 if reset:
171 known_paths = None
172 return known_paths
173
174def addsitepackages(known_paths):
175 """Add site-packages (and possibly site-python) to sys.path"""
176 prefixes = [sys.prefix]
177 if sys.exec_prefix != sys.prefix:
178 prefixes.append(sys.exec_prefix)
179 for prefix in prefixes:
180 if prefix:
181 if sys.platform in ('os2emx', 'os2knix', 'riscos'):
182 sitedirs = [os.path.join(prefix, "Lib", "site-packages")]
183 elif os.sep == '/':
184 sitedirs = [os.path.join(prefix,
185 "lib",
186 "python" + sys.version[:3],
187 "site-packages"),
188 os.path.join(prefix, "lib", "site-python")]
189 else:
190 sitedirs = [prefix, os.path.join(prefix, "lib", "site-packages")]
191 if sys.platform == 'darwin':
192 # for framework builds *only* we add the standard Apple
193 # locations. Currently only per-user, but /Library and
194 # /Network/Library could be added too
195 if 'Python.framework' in prefix:
196 home = os.environ.get('HOME')
197 if home:
198 sitedirs.append(
199 os.path.join(home,
200 'Library',
201 'Python',
202 sys.version[:3],
203 'site-packages'))
204 for sitedir in sitedirs:
205 if os.path.isdir(sitedir):
206 addsitedir(sitedir, known_paths)
207 return None
208
209
210def setBEGINLIBPATH():
211 """The OS/2 EMX port has optional extension modules that do double duty
212 as DLLs (and must use the .DLL file extension) for other extensions.
213 The library search path needs to be amended so these will be found
214 during module import. Use BEGINLIBPATH so that these are at the start
215 of the library search path.
216
217 """
218 dllpath = os.path.join(sys.prefix, "Lib", "lib-dynload")
219 libpath = os.environ['BEGINLIBPATH'].split(';')
220 if libpath[-1]:
221 libpath.append(dllpath)
222 else:
223 libpath[-1] = dllpath
224 os.environ['BEGINLIBPATH'] = ';'.join(libpath)
225
226
227def setquit():
228 """Define new built-ins 'quit' and 'exit'.
229 These are simply strings that display a hint on how to exit.
230
231 """
232 if os.sep == ':':
233 eof = 'Cmd-Q'
234 elif os.sep == '\\':
235 eof = 'Ctrl-Z plus Return'
236 else:
237 eof = 'Ctrl-D (i.e. EOF)'
238
239 class Quitter(object):
240 def __init__(self, name):
241 self.name = name
242 def __repr__(self):
243 return 'Use %s() or %s to exit' % (self.name, eof)
244 def __call__(self, code=None):
245 # Shells like IDLE catch the SystemExit, but listen when their
246 # stdin wrapper is closed.
247 try:
248 sys.stdin.close()
249 except:
250 pass
251 raise SystemExit(code)
252 __builtin__.quit = Quitter('quit')
253 __builtin__.exit = Quitter('exit')
254
255
256class _Printer(object):
257 """interactive prompt objects for printing the license text, a list of
258 contributors and the copyright notice."""
259
260 MAXLINES = 23
261
262 def __init__(self, name, data, files=(), dirs=()):
263 self.__name = name
264 self.__data = data
265 self.__files = files
266 self.__dirs = dirs
267 self.__lines = None
268
269 def __setup(self):
270 if self.__lines:
271 return
272 data = None
273 for dir in self.__dirs:
274 for filename in self.__files:
275 filename = os.path.join(dir, filename)
276 try:
277 fp = file(filename, "rU")
278 data = fp.read()
279 fp.close()
280 break
281 except IOError:
282 pass
283 if data:
284 break
285 if not data:
286 data = self.__data
287 self.__lines = data.split('\n')
288 self.__linecnt = len(self.__lines)
289
290 def __repr__(self):
291 self.__setup()
292 if len(self.__lines) <= self.MAXLINES:
293 return "\n".join(self.__lines)
294 else:
295 return "Type %s() to see the full %s text" % ((self.__name,)*2)
296
297 def __call__(self):
298 self.__setup()
299 prompt = 'Hit Return for more, or q (and Return) to quit: '
300 lineno = 0
301 while 1:
302 try:
303 for i in range(lineno, lineno + self.MAXLINES):
304 print self.__lines[i]
305 except IndexError:
306 break
307 else:
308 lineno += self.MAXLINES
309 key = None
310 while key is None:
311 key = raw_input(prompt)
312 if key not in ('', 'q'):
313 key = None
314 if key == 'q':
315 break
316
317def setcopyright():
318 """Set 'copyright' and 'credits' in __builtin__"""
319 __builtin__.copyright = _Printer("copyright", sys.copyright)
320 if sys.platform[:4] == 'java':
321 __builtin__.credits = _Printer(
322 "credits",
323 "Jython is maintained by the Jython developers (www.jython.org).")
324 else:
325 __builtin__.credits = _Printer("credits", """\
326 Thanks to CWI, CNRI, BeOpen.com, Zope Corporation and a cast of thousands
327 for supporting Python development. See www.python.org for more information.""")
328 here = os.path.dirname(os.__file__)
329 __builtin__.license = _Printer(
330 "license", "See http://www.python.org/%.3s/license.html" % sys.version,
331 ["LICENSE.txt", "LICENSE"],
332 [os.path.join(here, os.pardir), here, os.curdir])
333
334
335class _Helper(object):
336 """Define the built-in 'help'.
337 This is a wrapper around pydoc.help (with a twist).
338
339 """
340
341 def __repr__(self):
342 return "Type help() for interactive help, " \
343 "or help(object) for help about object."
344 def __call__(self, *args, **kwds):
345 import pydoc
346 return pydoc.help(*args, **kwds)
347
348def sethelper():
349 __builtin__.help = _Helper()
350
351def aliasmbcs():
352 """On Windows, some default encodings are not provided by Python,
353 while they are always available as "mbcs" in each locale. Make
354 them usable by aliasing to "mbcs" in such a case."""
355 if sys.platform == 'win32':
356 import locale, codecs
357 enc = locale.getdefaultlocale()[1]
358 if enc.startswith('cp'): # "cp***" ?
359 try:
360 codecs.lookup(enc)
361 except LookupError:
362 import encodings
363 encodings._cache[enc] = encodings._unknown
364 encodings.aliases.aliases[enc] = 'mbcs'
365
366def setencoding():
367 """Set the string encoding used by the Unicode implementation. The
368 default is 'ascii', but if you're willing to experiment, you can
369 change this."""
370 encoding = "ascii" # Default value set by _PyUnicode_Init()
371 if 0:
372 # Enable to support locale aware default string encodings.
373 import locale
374 loc = locale.getdefaultlocale()
375 if loc[1]:
376 encoding = loc[1]
377 if 0:
378 # Enable to switch off string to Unicode coercion and implicit
379 # Unicode to string conversion.
380 encoding = "undefined"
381 if encoding != "ascii":
382 # On Non-Unicode builds this will raise an AttributeError...
383 sys.setdefaultencoding(encoding) # Needs Python Unicode build !
384
385
386def execsitecustomize():
387 """Run custom site specific code, if available."""
388 try:
389 import sitecustomize
390 except ImportError:
391 pass
392
393
394def main():
395 abs__file__()
396 paths_in_sys = removeduppaths()
397 if (os.name == "posix" and sys.path and
398 os.path.basename(sys.path[-1]) == "Modules"):
399 addbuilddir()
400 paths_in_sys = addsitepackages(paths_in_sys)
401 if sys.platform == 'os2emx' or sys.platform == 'os2knix':
402 if (sys.path and os.path.basename(sys.path[-1]) == "Modules"):
403 addbuilddir()
404 setBEGINLIBPATH()
405 setquit()
406 setcopyright()
407 sethelper()
408 aliasmbcs()
409 setencoding()
410 execsitecustomize()
411 # Remove sys.setdefaultencoding() so that users cannot change the
412 # encoding after initialization. The test for presence is needed when
413 # this module is run as a script, because this code is executed twice.
414 if hasattr(sys, "setdefaultencoding"):
415 del sys.setdefaultencoding
416
417main()
418
419def _test():
420 print "sys.path = ["
421 for dir in sys.path:
422 print " %r," % (dir,)
423 print "]"
424
425if __name__ == '__main__':
426 _test()
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