Mel <mwilson at the-wire.com> writes: > def file_to_hash(path, m = hashlib.md5()): >> hashlib.md5 *is* called once; that is when the def statement is executed. Very interesting, I certainly wasn't clear on this. So after that def, the created hashlib object is in the module's scope and can be accessed via file_to_hash.__defaults__[0].