When you dump the data, make sure you specify the protocol to use:
with open('dict.obj', 'wb') as fh:
pickle.dump(obj, fh, pickle.HIGHEST_PROTOCOL)
And when loading, you should see a speed increese if you switch to Python 3 (if possible).
with open('dict.obj', 'rb') as fh:
return pickle.load(fh)
Also storing the pickled file on a separate medium would be reccommended. Because running everything from the same device will slow down the reading process.