Save a class into a binary file - Python

Question

I'm aware that saving a class into a binary file in c++ is possible using:

file.write(Class_variable, size_of_class, amount_of_saves, file_where_to_save)

or something similar, and I wanted to use that in python in order to make it easier to write and read lots of data.

I've tried to do this:

def Save_Game(player, room):
    address = 'Saves/player'

    file = open(address, 'wb')
    file.write(player)

    address = 'Saves/room'

    file = open(address, 'wb')
    file.write(room)

Room and player being class_objects. But it says:

TypeError: must be convertible to a buffer, not PlayerMarty

What can I do?

Solution 1

pickle is what you need. The pickle module implements a fundamental, but powerful algorithm for serializing and de-serializing a Python object structure. This is an example

import pickle

class MyClass:
    def __init__(self,name):
        self.name = name
    def display(self):
        print(self.name)

my = MyClass("someone")
pickle.dump(my, open("myobject", "wb"))
me = pickle.load(open("myobject", "rb"))
me.display()

Solution 2

You can get at the bytes of Python objects to save & restore them like that, but it's not easy to do directly. However, the standard pickle module simplifies the process enormously.