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annotate Doc/library/user.rst @ 54294:dba767bc3155 legacy-trunk

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remove mention of old ctypes version
author Benjamin Peterson <benjamin@python.org>
date Sat, 23 May 2009 20:59:09 +0000
parents c15cf01415f9
children 8aab13719c02
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2 :mod:`user` --- User-specific configuration hook
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3 ================================================
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5 .. module:: user
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6 :synopsis: A standard way to reference user-specific modules.
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fb1984fb182d Deprecate the user module for removal in 3.0.
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7 :deprecated:
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439269485569 Fix some errors in the deprecation warnings for new and user.
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9 .. deprecated:: 2.6
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10 The :mod:`user` module has been removed in Python 3.0.
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12 .. index::
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13 pair: .pythonrc.py; file
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14 triple: user; configuration; file
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16 As a policy, Python doesn't run user-specified code on startup of Python
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17 programs. (Only interactive sessions execute the script specified in the
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18 :envvar:`PYTHONSTARTUP` environment variable if it exists).
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20 However, some programs or sites may find it convenient to allow users to have a
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21 standard customization file, which gets run when a program requests it. This
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22 module implements such a mechanism. A program that wishes to use the mechanism
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23 must execute the statement ::
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25 import user
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27 .. index:: builtin: execfile
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29 The :mod:`user` module looks for a file :file:`.pythonrc.py` in the user's home
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30 directory and if it can be opened, executes it (using :func:`execfile`) in its
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31 own (the module :mod:`user`'s) global namespace. Errors during this phase are
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32 not caught; that's up to the program that imports the :mod:`user` module, if it
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33 wishes. The home directory is assumed to be named by the :envvar:`HOME`
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34 environment variable; if this is not set, the current directory is used.
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36 The user's :file:`.pythonrc.py` could conceivably test for ``sys.version`` if it
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37 wishes to do different things depending on the Python version.
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39 A warning to users: be very conservative in what you place in your
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40 :file:`.pythonrc.py` file. Since you don't know which programs will use it,
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41 changing the behavior of standard modules or functions is generally not a good
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42 idea.
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44 A suggestion for programmers who wish to use this mechanism: a simple way to let
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45 users specify options for your package is to have them define variables in their
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46 :file:`.pythonrc.py` file that you test in your module. For example, a module
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47 :mod:`spam` that has a verbosity level can look for a variable
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48 ``user.spam_verbose``, as follows::
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50 import user
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52 verbose = bool(getattr(user, "spam_verbose", 0))
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54 (The three-argument form of :func:`getattr` is used in case the user has not
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55 defined ``spam_verbose`` in their :file:`.pythonrc.py` file.)
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57 Programs with extensive customization needs are better off reading a
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58 program-specific customization file.
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60 Programs with security or privacy concerns should *not* import this module; a
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61 user can easily break into a program by placing arbitrary code in the
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62 :file:`.pythonrc.py` file.
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64 Modules for general use should *not* import this module; it may interfere with
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65 the operation of the importing program.
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68 .. seealso::
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70 Module :mod:`site`
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71 Site-wide customization mechanism.
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72