def is_extension_module(filename):
    return os.path.splitext(filename)[1].lower() in ('.so','.pyd')
assert that we are ordered
dataset/ETHPy150Open ipython/ipython-py3k/IPython/testing/plugin/ipdoctest.py/is_extension_module--crossover with--dataset/ETHPy150Open pydata/pandas/pandas/core/categorical.py/Categorical.check_for_ordered