1 2:mod:`user` --- User-specific configuration hook 3================================================ 4 5.. module:: user 6 :synopsis: A standard way to reference user-specific modules. 7 :deprecated: 8 9.. deprecated:: 2.6 10 The :mod:`user` module has been removed in Python 3. 11 12.. index:: 13 pair: .pythonrc.py; file 14 triple: user; configuration; file 15 16As a policy, Python doesn't run user-specified code on startup of Python 17programs. (Only interactive sessions execute the script specified in the 18:envvar:`PYTHONSTARTUP` environment variable if it exists). 19 20However, some programs or sites may find it convenient to allow users to have a 21standard customization file, which gets run when a program requests it. This 22module implements such a mechanism. A program that wishes to use the mechanism 23must execute the statement :: 24 25 import user 26 27.. index:: builtin: execfile 28 29The :mod:`user` module looks for a file :file:`.pythonrc.py` in the user's home 30directory and if it can be opened, executes it (using :func:`execfile`) in its 31own (the module :mod:`user`'s) global namespace. Errors during this phase are 32not caught; that's up to the program that imports the :mod:`user` module, if it 33wishes. The home directory is assumed to be named by the :envvar:`HOME` 34environment variable; if this is not set, the current directory is used. 35 36The user's :file:`.pythonrc.py` could conceivably test for ``sys.version`` if it 37wishes to do different things depending on the Python version. 38 39A warning to users: be very conservative in what you place in your 40:file:`.pythonrc.py` file. Since you don't know which programs will use it, 41changing the behavior of standard modules or functions is generally not a good 42idea. 43 44A suggestion for programmers who wish to use this mechanism: a simple way to let 45users specify options for your package is to have them define variables in their 46:file:`.pythonrc.py` file that you test in your module. For example, a module 47:mod:`spam` that has a verbosity level can look for a variable 48``user.spam_verbose``, as follows:: 49 50 import user 51 52 verbose = bool(getattr(user, "spam_verbose", 0)) 53 54(The three-argument form of :func:`getattr` is used in case the user has not 55defined ``spam_verbose`` in their :file:`.pythonrc.py` file.) 56 57Programs with extensive customization needs are better off reading a 58program-specific customization file. 59 60Programs with security or privacy concerns should *not* import this module; a 61user can easily break into a program by placing arbitrary code in the 62:file:`.pythonrc.py` file. 63 64Modules for general use should *not* import this module; it may interfere with 65the operation of the importing program. 66 67 68.. seealso:: 69 70 Module :mod:`site` 71 Site-wide customization mechanism. 72 73