Modules available for Serialization and Deserialization in Python

Python provides three different modules which allow us to serialize and deserialize objects :  

1. Marshal Module
2. Pickle Module
3. JSON Module

1. Marshal Module: It is the oldest module among these three. It is mainly used to read and write the compiled byte code of Python modules. Even we can use marshal to serialize Python objects, but it is not recommended to use. It is mainly used by the interpreter and the official documentation warns that the python maintainers may modify the format in backward-incompatible ways.

Note: It is recommended to never unmarshal data received from an untrusted or unauthenticated source.  

Example : 

Python3

# importing the module
import marshal

data = {'name': 'sunny','age': 34,'address': 'nasik'}

# dumps() return byte object stored in variable 'bytes'
bytes = marshal.dumps(data)
print('After serialization : ', bytes)

# loads() convert byte object to value
new_data = marshal.loads(bytes)
print('After deserialization : ', new_data)

Output:

After serialization :  b’\xfb\xda\x04name\xda\x05sunny\xda\x03age\xe9″\x00\x00\x00\xda\x07address\xda\x05nasik0′

After deserialization :  {‘name’: ‘sunny’, ‘age’: 34, ‘address’: ‘nasik’} 

2. Pickle Module: It is another way to serialize and deserialize Python objects. It serializes the Python object in a binary format, due to which it is not human-readable. It is faster and it also works with custom-defined objects. The Python pickle module is a better choice for serialization and deserialization of python objects. If you don’t need a human-readable format or if you need to serialize custom objects then it is recommended to use the pickle module. 

Example: 

Python3

# importinig the module
import pickle

data = {'st_name': 'Sunny', 'st_id': '9607', 'st_add': 'Nasik'}
with open('data.pickle', 'wb') as f1 :

    # converts object to byte stream(list, dict, etc.)
    pickle.dump(data, f1)
    print('Pickling Completed...')

with open('data.pickle', 'rb') as f2 :
    print('Unpickling the data : ')

    # converts byte stream(generated through pickling)back into object
    data = pickle.load(f2)
    print(data)

Output:

Pickling Completed...
Unpickling the data : 
{'st_name': 'Sunny', 'st_id': '9607', 'st_add': 'Nasik'}

3. JSON Module: It is a newly created module. It allows us to work with standard JSON files. JSON is a widely used format for data exchange and it is very convenient. It is human-readable and language-independent, and it’s lighter than XML. Using the JSON module we can serialize and deserialize several standard Python types like bool, dict, int, float, list, string, tuple, none etc. The JSON module and XML are a good choice if we want to interoperability among different languages. 

Example: Deserializing

Python3

# importing the module
import json

# JSON string
students = '{"id":"9607", "name": "Sunny", "department":"Computer"}'

# convert string to Python dict
student_dict = json.loads(students)
print(student_dict)

print(student_dict['name'])
print('Deserialization Completed.')

Output:

{"id": "9607", "name": "Sunny", "department":"Computer"}
Sunny
Deserialization Completed.

Example: Serializing

Python3

# importing the module
import json

data = {
  "id": "877",
  "name": "Mayur",
  "department": "Comp"
}

# Serializing json
json_object = json.dumps(data)
print(json_object)
print('Serialization Completed.')

Output

{"id": "877", "name": "Mayur", "department": "Comp"}
Serialization Completed.

Output:

{"id": "877", "name": "Mayur", "department": "Comp"}
Serialization Completed.