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75 lines
2.7 KiB
TeX
75 lines
2.7 KiB
TeX
\section{Standard Module \sectcode{site}}
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\label{module-site}
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\stmodindex{site}
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\strong{This module is automatically imported during initialization.}
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In earlier versions of Python (up to and including 1.5a3), scripts or
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modules that needed to use site-specific modules would place
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\code{import site} somewhere near the top of their code. This is no
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longer necessary.
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This will append up site-specific paths to to the module search path.
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It starts with \code{sys.prefix} and \code{sys.exec_prefix} (if
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different) and appends \file{lib/python\var{version}/packages}. The
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resulting directory, if it exists, is added to \code{sys.path}, and
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also inspected for path configuration files. A path configuration
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file is a file whose name has the form \file{\var{package}.pth}; its
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contents are additional directories (one per line) to be added to
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\code{sys.path}. Non-existing directories (or non-directories) are
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never added to \code{sys.path}; no directory is added to
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\code{sys.path} more than once. Blank lines and lines beginning with
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\code{\#} are skipped.
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\index{package}
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\kwindex{sys.prefix}
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\kwindex{sys.exec_prefix}
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\kwindex{prefix}
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\kwindex{exec_prefix}
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For example, suppose \code{sys.prefix} and \code{sys.exec_prefix} are
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set to \file{/usr/local}. The Python 1.5 library is then installed in
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\file{/usr/local/lib/python1.5}. Suppose this has a subdirectory
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\file{/usr/local/python1.5/packages} with three subsubdirectories,
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\file{foo}, \file{bar} and \file{spam}, and two path configuration
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files, \file{foo.pth} and \file{bar.pth}. Assume \file{foo.pth}
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contains the following:
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\bcode\begin{verbatim}
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# foo package configuration
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foo
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bar
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bletch
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\end{verbatim}\ecode
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and \file{bar.pth} contains:
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\bcode\begin{verbatim}
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# bar package configuration
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bar
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\end{verbatim}\ecode
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Then the following directories are added to sys.path, in this order:
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\bcode\begin{verbatim}
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/usr/local/python1.5/packages/bar
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/usr/local/python1.5/packages/foo
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\end{verbatim}\ecode
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Note that \file{bletch} is omitted because it doesn't exist; the
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\file{bar} directory precedes the \file{foo} directory because
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\file{bar.pth} comes alphabetically before \file{foo.pth}; and
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\file{spam} is omitted because it is not mentioned in either path
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configuration file.
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After these path manipulations, an attempt is made to import a module
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named \code{sitecustomize}, which can perform arbitrary site-specific
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customizations. If this import fails with an \code{ImportError}
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exception, it is silently ignored.
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\stmodindex{sitecustomize}
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Note that for some non-Unix systems, \code{sys.prefix} and
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\code{sys.exec_prefix} are empty, and the path manipulations are
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skipped; however the import of \code{sitecustomize} is still attempted.
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