A simple memoize function that writes json out to a file, momoizing between python executions

load_or_build.py

import json
import functools

def load_or_build(filename):
    def wraps(fun):
        @functools.wraps(fun)
        def wrapped(*args, **kwargs):
            try:
                f = file(filename)
                return json.load(f)
            except IOError:
                d = fun(*args, **kwargs)
                f = file(filename, 'w')
                json.dump(d, f, indent=2)
                f.close()
                return d
        return wrapped
    return wraps