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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_modpkg_path(dotted_name, pathlist=None):
 """Get the filesystem path for a module or a package. Return the file system path to a file for a module, and to a directory for a package. Return None if the name is not found, or is a builtin or extension module. """

    # split off top-most name
    parts = dotted_name.split('.', 1)

    if len(parts) > 1:
        # we have a dotted path, import top-level package
        try:
            file, pathname, description = imp.find_module(parts[0], pathlist)
            if file: file.close()
        except ImportError:
            return None

        # check if it's indeed a package
        if description[2] == imp.PKG_DIRECTORY:
            # recursively handle the remaining name parts
            pathname = _get_modpkg_path(parts[1], [pathname])
        else:
            pathname = None
    else:
        # plain name
        try:
            file, pathname, description = imp.find_module(
                dotted_name, pathlist)
            if file:
                file.close()
            if description[2] not in [imp.PY_SOURCE, imp.PKG_DIRECTORY]:
                pathname = None
        except ImportError:
            pathname = None

    return pathname