3.8.1. Examples

import imp

import sys


def __import__(name, globals=None, locals=None, fromlist=None):

    # Fast path: see if the module has already been imported.

    if sys.modules.has_key(name):

        return sys.modules[name]


    # If any of the following calls raises an exception,

    # there's a problem we can't handle -- let the caller handle it.


    # See if it's a built-in module.

    m = imp.init_builtin(name)

    if m:

        return m


    # See if it's a frozen module.

    m = imp.init_frozen(name)

    if m:

        return m


    # Search the default path (i.e. sys.path).

    fp, pathname, (suffix, mode, type) = imp.find_module(name)


    # See what we got.

    try:

        if type == imp.C_EXTENSION:

            return imp.load_dynamic(name, pathname)

        if type == imp.PY_SOURCE:

            return imp.load_source(name, pathname, fp)

        if type == imp.PY_COMPILED:

            return imp.load_compiled(name, pathname, fp)


        # Shouldn't get here at all.

        raise ImportError, '%s: unknown module type (%d)' % (name, type)

    finally:

        # Since we may exit via an exception, close fp explicitly.

        fp.close()