The role of pickle:

1: pickle.dump(dict,file) converts the dictionary to base 2 and stores it in a file.

2: pickle. load(file) converts the file’s base 2 content into a dictionary

import pickle

#  increase
def adds():
  users = {"name":"yangbin", "age":22, "sex":"male"}
  with open("red.txt", "wb") as f:
    pickle.dump(users, f)
  dic = {}
  with open("red.txt") as sd:
    dic = pickle.load(sd)
  print dic

#  delete
def deletes():
  dic = {}
  with open("red.txt") as f:
    dic = pickle.load(f)
  dic.pop("sex")
  with open("red.txt", "wb") as ff:
    pickle.dump(dic, ff)
  print dic

#  change
def changes():
  dic = {}
  with open("red.txt") as f:
    dic = pickle.load(f)
  dic["age"] = 28
  with open("red.txt", "wb") as f:
    pickle.dump(dic, f)
  print dic

#  check
def finds():
  dic = {}
  with open("red.txt") as f:
    dic = pickle.load(f)
  for k,v in dic.items():
    print "%s ---> %s" % (k, v)

adds()
deletes()
changes()
finds()

Operation results:

root@python3:/python/python2/linshi# python 01.py
{'age': 22, 'name': 'yangbin', 'sex': 'male'}
{'age': 22, 'name': 'yangbin'}
{'age': 28, 'name': 'yangbin'}
age ---> 28
name ---> yangbin
root@python3:/python/python2/linshi#