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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 resource_listdir(package_or_requirement, relative_path):
 """ Similar to pkg_resources.resource_listdir but if the resource it not found via pkg_resources it also looks in a predefined list of paths in order to find the resource :param package_or_requirement: the module in which the resource resides :param relative_path: the relative path to the resource :return: a list of all files residing in the target path :rtype: list """

    path = resource_filename(package_or_requirement, relative_path)
    only_files = [f for f in listdir(path) if isfile(join(path, f))]
    return only_files