I have recently got an assignment where I need to put a dictionary (where each key refers to a list) in pickled form. The only problem is I have no idea what pickled form is. Could anyone point me in the right direction of some good resources to help me learn this concept?
The pickle module implements a fundamental, but powerful algorithm for serializing and de-serializing a Python object structure.
Pickling - is the process whereby a Python object hierarchy is converted into a byte stream, and Unpickling - is the inverse operation, whereby a byte stream is converted back into an object hierarchy.
Pickling (and unpickling) is alternatively known as serialization, marshalling, or flattening.
import pickle
data1 = {'a': [1, 2.0, 3, 4+6j],
'b': ('string', u'Unicode string'),
'c': None}
selfref_list = [1, 2, 3]
selfref_list.append(selfref_list)
output = open('data.pkl', 'wb')
# Pickle dictionary using protocol 0.
pickle.dump(data1, output)
# Pickle the list using the highest protocol available.
pickle.dump(selfref_list, output, -1)
output.close()
To read from a pickled file -
import pprint, pickle
pkl_file = open('data.pkl', 'rb')
data1 = pickle.load(pkl_file)
pprint.pprint(data1)
data2 = pickle.load(pkl_file)
pprint.pprint(data2)
pkl_file.close()