We need to pickle any sort of callable

Question

Recently a question was posed regarding some Python code attempting to facilitate distributed computing through the use of pickled processes. Apparently, that functionality

Answer 1

You could marshal the bytecode and pickle the other function things:

import marshal
import pickle

marshaled_bytecode = marshal.dumps(your_function.func_code)
# In this process, other function things are lost, so they have to be sent separated.
pickled_name = pickle.dumps(your_function.func_name)
pickled_arguments = pickle.dumps(your_function.func_defaults)
pickled_closure = pickle.dumps(your_function.func_closure)
# Send the marshaled bytecode and the other function things through a socket (they are byte strings).
send_through_a_socket((marshaled_bytecode, pickled_name, pickled_arguments, pickled_closure))

In another python program:

import marshal
import pickle
import types

# Receive the marshaled bytecode and the other function things.
marshaled_bytecode, pickled_name, pickled_arguments, pickled_closure = receive_from_a_socket()
your_function = types.FunctionType(marshal.loads(marshaled_bytecode), globals(), pickle.loads(pickled_name), pickle.loads(pickled_arguments), pickle.loads(pickled_closure))

And any references to globals inside the function would have to be recreated in the script that receives the function.

In Python 3, the function attributes used are __code__, __name__, __defaults__ and __closure__.

Please do note that send_through_a_socket and receive_from_a_socket do not actually exist, and you should replace them by actual code that transmits data through sockets.