Sometimes you may need to temporarily store data so it can be accessed directly the next time the program runs, or used for inter-thread data exchange. Serialization helps with this. Here, we explain Python’s serialization and deserialization using the pickle package.

What Are Serialization and Deserialization?

  • Serialization: Converting Python data into a binary data stream.
  • Deserialization: Converting a binary data stream back into a Python object.

Using Python’s pickle Module

  • dumps(): This function converts Python objects into a data stream.
  • loads(): This function restores the stored data stream back into Python objects.

Below is an example of using pickle for serialization and deserialization in Python.

pickle Example: Using a File

  1. pickle.dump(obj, file, protocol=None, *, fix_imports=True)
import pickle 
  
def storeData(): 
    # Initialize data
    chunjiang = {'key' : 'chunjiang', 'name' : 'zhang chunjiang', 
    'age' : 18, 'pay' : 100} 
    muke = {'key' : 'muke', 'name' : 'li muke', 
    'age' : 40, 'pay' : 500} 
  
    # Database
    db = {} 
    db['chunjiang'] = chunjiang 
    db['muke'] = muke 
      
    # Binary mode
    dbfile = open('lizi_pickle', 'ab') 
      
    # Store
    pickle.dump(db, dbfile)                      
    dbfile.close() 
  
def loadData(): 
    # Load data
    dbfile = open('lizi_pickle', 'rb')      
    db = pickle.load(dbfile) 
    for keys in db: 
        print(keys, '=>', db[keys]) 
    dbfile.close() 
  
if __name__ == '__main__': 
    storeData() 
    loadData()

Output:

pickle

pickle Example: Without Using a File

import pickle
chunjiang = {'key' : 'chunjiang', 'name' : 'zhang chunjiang', 
    'age' : 18, 'pay' : 100}
muke = {'key' : 'muke', 'name' : 'li muke', 
    'age' : 40, 'pay' : 500} 
  
# Database
db = {} 
db['chunjiang'] = chunjiang 
db['muke'] = muke 
  
# Serialize
b = pickle.dumps(db)       # type(b) gives <class 'bytes'> 
  
# Deserialize
mydata = pickle.loads(b) 
print(mydata)

pickle_no_file

Summary

This blog mainly gives a brief introduction and detailed code examples on data serialization and deserialization in Python.