A Python script to read/write pickle files

readwrite_pkl.py

import cPickle as pickle

ongoing_list_dict = dict(subject_1 = 7,
                         subject_7 = 42,
                         subject_101 = 3)

# Write the dictionary to file
with open('ongoing_list.pkl', 'wb') as f:
    pickle.dump(ongoing_list_dict, f,  protocol=2)

# Read it back in
with open('ongoing_list.pkl', 'rb') as f:
    ongoing_list_dict_2 = pickle.load(f)

# Prove the original and read-back-in dictionary are identical
assert ongoing_list_dict_2 == ongoing_list_dict

# To save effort, if you are doing a lot of reading/writing,
# use the following functions
def write_pickle(obj, fname='ongoing_list.pkl'):
    with open(fname, 'wb') as f:
        pickle.dump(obj, f, protocol=2)

def read_pickle(fname='ongoing_list.pkl'):
    with open(fname, 'rb') as f:
        return pickle.load(f)

# Check they work
ongoing_list_dict['subject_5'] = 42
write_pickle(ongoing_list_dict)
assert read_pickle() == ongoing_list_dict