3.21 Standard Module site

 

This module is automatically imported during initialization.

In earlier versions of Python (up to and including 1.5a3), scripts or modules that needed to use site-specific modules would place "import site" somewhere near the top of their code. This is no longer necessary.

This will append site-specific paths to to the module search path.  

It starts by constructing up to four directories from a head and a tail part. For the head part, it uses sys.prefix and sys.exec_prefix; empty heads are skipped. For the tail part, it uses the empty string (on Macintosh or Windows) or it uses first "lib/pythonversion/site-packages" and then "lib/site-python" (on Unix). For each of the distinct head-tail combinations, it sees if it refers to an existing directory, and if so, adds 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 items (one per line) to be added to sys.path. Non-existing items are never added to sys.path, but no check is made that the item refers to a directory (rather than a file). No item is added to sys.path more than once. Blank lines and lines beginning with # are skipped.   

For example, suppose sys.prefix and sys.exec_prefix are set to "/usr/local". The Python 1.5.1 library is then installed in "/usr/local/lib/python1.5" (note that only the first three characters of sys.version are used to form the path name). Suppose this has a subdirectory "/usr/local/lib/python1.5/site-packages" with three subsubdirectories, "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; the "bar" directory precedes the "foo" directory 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 silently ignored.

Note that for some 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.