:mod:`modulefinder` --- Find modules used by a script
=====================================================

.. sectionauthor:: A.M. Kuchling <amk@amk.ca>


.. module:: modulefinder
   :synopsis: Find modules used by a script.

**Source code:** :source:`Lib/modulefinder.py`

--------------

This module provides a :class:`ModuleFinder` class that can be used to determine
the set of modules imported by a script. ``modulefinder.py`` can also be run as
a script, giving the filename of a Python script as its argument, after which a
report of the imported modules will be printed.


.. function:: AddPackagePath(pkg_name, path)

   Record that the package named *pkg_name* can be found in the specified *path*.


.. function:: ReplacePackage(oldname, newname)

   Allows specifying that the module named *oldname* is in fact the package named
   *newname*.


.. class:: ModuleFinder(path=None, debug=0, excludes=[], replace_paths=[])

   This class provides :meth:`run_script` and :meth:`report` methods to determine
   the set of modules imported by a script. *path* can be a list of directories to
   search for modules; if not specified, ``sys.path`` is used.  *debug* sets the
   debugging level; higher values make the class print debugging messages about
   what it's doing. *excludes* is a list of module names to exclude from the
   analysis. *replace_paths* is a list of ``(oldpath, newpath)`` tuples that will
   be replaced in module paths.


   .. method:: report()

      Print a report to standard output that lists the modules imported by the
      script and their paths, as well as modules that are missing or seem to be
      missing.

   .. method:: run_script(pathname)

      Analyze the contents of the *pathname* file, which must contain Python
      code.

   .. attribute:: modules

      A dictionary mapping module names to modules. See
      :ref:`modulefinder-example`.


.. _modulefinder-example:

Example usage of :class:`ModuleFinder`
--------------------------------------

The script that is going to get analyzed later on (bacon.py)::

   import re, itertools

   try:
       import baconhameggs
   except ImportError:
       pass

   try:
       import guido.python.ham
   except ImportError:
       pass


The script that will output the report of bacon.py::

   from modulefinder import ModuleFinder

   finder = ModuleFinder()
   finder.run_script('bacon.py')

   print('Loaded modules:')
   for name, mod in finder.modules.items():
       print('%s: ' % name, end='')
       print(','.join(list(mod.globalnames.keys())[:3]))

   print('-'*50)
   print('Modules not imported:')
   print('\n'.join(finder.badmodules.keys()))

Sample output (may vary depending on the architecture)::

    Loaded modules:
    _types:
    copyreg:  _inverted_registry,_slotnames,__all__
    sre_compile:  isstring,_sre,_optimize_unicode
    _sre:
    sre_constants:  REPEAT_ONE,makedict,AT_END_LINE
    sys:
    re:  __module__,finditer,_expand
    itertools:
    __main__:  re,itertools,baconhameggs
    sre_parse:  _PATTERNENDERS,SRE_FLAG_UNICODE
    array:
    types:  __module__,IntType,TypeType
    ---------------------------------------------------
    Modules not imported:
    guido.python.ham
    baconhameggs


