Deep copy implementation for Python with a fast path that uses `marshal`

deepcopy.py

import copy
import marshal


def marshal_deepcopy(obj):
    """
    Deep copy implementation that uses `marshal` for increased speed if possible,
    falling back to `copy.deepcopy` if the passed object is not marshallable.
    """
    try:
        return marshal.loads(marshal.dumps(obj))
    except ValueError:
        return copy.deepcopy(obj)