"""Helper to provide extensibility for pickle/cPickle.
This is only useful to add pickle support for extension types defined in
C, not for instances of user-defined classes.
"""
from types import ClassType
__all__ = ["pickle","constructor"]
dispatch_table = {}
safe_constructors = {}
def pickle(ob_type, pickle_function, constructor_ob=None):
if type(ob_type) is _ClassType:
raise TypeError("copy_reg is not intended for use with classes")
if not callable(pickle_function):
raise TypeError("reduction functions must be callable")
dispatch_table[ob_type] = pickle_function
if constructor_ob is not None:
constructor(constructor_ob)
def constructor(object):
if not callable(object):
raise TypeError("constructors must be callable")
safe_constructors[object] = 1
# Example: provide pickling support for complex numbers.
def pickle_complex(c):
return complex, (c.real, c.imag)
pickle(type(1j), pickle_complex, complex)
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