pyyaml/tests/lib/test_all.py

import sys, yaml, test_appliance

def main(args=None):
    collections = []
    import test_yaml
    collections.append(test_yaml)
    if yaml.__with_libyaml__:
        import test_yaml_ext
        collections.append(test_yaml_ext)
    return test_appliance.run(collections, args)

if __name__ == '__main__':
    main()