diff options
Diffstat (limited to 'Lib/site.py')
| -rw-r--r-- | Lib/site.py | 131 |
1 files changed, 103 insertions, 28 deletions
diff --git a/Lib/site.py b/Lib/site.py index d2420cf..c323a91 100644 --- a/Lib/site.py +++ b/Lib/site.py @@ -1,47 +1,122 @@ -"""Hook to allow easy access to site-specific modules. +"""Append module search paths for third-party packages to sys.path. -Scripts or modules that need to use site-specific modules should place +**************************************************************** +* This module is automatically imported during initialization. * +**************************************************************** - import site +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). -somewhere near the top of their code. This will append up to two -site-specific paths ($prefix/lib/site-python and -$exec_prefix/lib/site-python) to the module search path. ($prefix -and $exec_prefix are configuration parameters, and both default -to /usr/local; they are accessible in Python as sys.prefix and -sys.exec_prefix). +This will append site-specific paths to to the module search path. It +starts with sys.prefix and sys.exec_prefix (if different) and appends +lib/python<version>/packages. The resulting directory, if it exists, +is added to sys.path, and also inspected for path configuration files. -Because of Python's import semantics, it is okay for more than one -module to import site -- only the first one will execute the site -customizations. The directories are only appended to the path if they -exist and are not already on it. +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. -Sites that wish to provide site-specific modules should place them in -one of the site specific directories; $prefix/lib/site-python is for -Python source code and $exec_prefix/lib/site-python is for dynamically -loadable extension modules (shared libraries). +For example, suppose sys.prefix and sys.exec_prefix are set to +/usr/local and there is a directory /usr/local/python1.5/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/packages/bar + /usr/local/lib/python1.5/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 site-specific -customizations. If this import fails with an ImportError exception, -it is ignored. +named sitecustomize, which can perform arbitrary additional +site-specific customizations. If this import fails with an +ImportError exception, it is silently ignored. -Note that for non-Unix systems, sys.prefix and sys.exec_prefix are -empty, and the path manipulations are skipped; however the import of -sitecustomize is still attempted. +Note that for some non-Unix systems, sys.prefix and sys.exec_prefix +are empty, and then the path manipulations are skipped; however the +import of sitecustomize is still attempted. -XXX Any suggestions as to how to handle this for non-Unix systems??? """ +print "loading site.py" + import sys, os -for prefix in sys.prefix, sys.exec_prefix: +def addsitedir(sitedir): + if sitedir not in sys.path: + sys.path.append(sitedir) # Add path component + try: + names = os.listdir(sitedir) + except os.error: + return + names = map(os.path.normcase, names) + names.sort() + for name in names: + if name[-4:] == ".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[-1] == '\n': + dir = dir[:-1] + dir = os.path.join(sitedir, dir) + if dir not in sys.path and os.path.exists(dir): + sys.path.append(dir) + +prefixes = [sys.prefix] +if sys.exec_prefix != sys.prefix: + prefixes.append(sys.exec_prefix) +for prefix in prefixes: if prefix: - sitedir = os.path.join(prefix, os.path.join("lib", "site-python")) - if sitedir not in sys.path and os.path.isdir(sitedir): - sys.path.append(sitedir) # Add path component + if sys.platform[:3] in ('win', 'mac'): + sitedir = prefix + else: + sitedir = os.path.join(prefix, + "lib", + "python" + sys.version[:3], + "packages") + if os.path.isdir(sitedir): + addsitedir(sitedir) try: import sitecustomize # Run arbitrary site specific code except ImportError: pass # No site customization module + +def _test(): + print "sys.path = [" + for dir in sys.path: + print " %s," % `dir` + print "]" + +if __name__ == '__main__': + _test() |