This recipe is a followup of the Copying Generators recipe. It defines a GeneratorSnapshot object that stores all relevant data of a running generator but being serializable by pickle. During unpickling the generator is restored from the snapshot.
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#
# W A R N I N G
#
# This recipe is obsolete!
#
# When you are looking for copying and pickling functionality for generators
# implemented in pure Python download the
#
# generator_tools
#
# package at the cheeseshop or at www.fiber-space.de
#
###
import pickle
import types
class any_obj:
"Used to create objects for spawning arbitrary attributes by assignment"
class GeneratorSnapshot(object):
'''
Object used to hold data for living generators.
'''
def __init__(self, f_gen):
f_code = f_gen.gi_frame.f_code
self.gi_frame = any_obj()
self.gi_frame.f_code = any_obj()
self.gi_frame.f_code.__dict__.update((key, getattr(f_code, key))
for key in dir(f_code) if key.startswith("co_"))
self.gi_frame.f_lasti = f_gen.gi_frame.f_lasti
self.gi_frame.f_locals = {}
for key, value in f_gen.gi_frame.f_locals.items():
if isinstance(value, types.GeneratorType):
self.gi_frame.f_locals[key] = GeneratorSnapshot(value)
else:
self.gi_frame.f_locals[key] = value
def pickle_generator(f_gen, filename):
'''
@param f_gen: generator object
@param filename: destination file for pickling generator
'''
output_pkl = open(filename, "wb")
pickle.dump(GeneratorSnapshot(f_gen), output_pkl)
def unpickle_generator(filename):
'''
@param filename: source file of pickled generator
'''
input_pkl = open(filename, "rb")
gen_snapshot = pickle.load(input_pkl)
return copy_generator(gen_snapshot)[0]
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Tags: algorithms
Runtime error. Running this code, I get the error
</pre>
Problem fixed. The GeneratorSnapshot shall not contain unbound variables anymore ( the types module as an exception ).