How to Create a Simple Login System in Python

In this example we will show how to implement a simple login system with Python.

Source Code

#! /usr/bin/env python3
# -*- coding: utf-8 -*-

credential = {"John" : "123a", "Jack" : "456b"}
success = False
for i in range(3):
    username = input("please enter your username: ")
    password = input("please enter your password: ")
    if (credential.get(username) == password):
        print("login succeeded")
        success = True
        break
    else:
        print("login failed")
if not success:
    print("\nYour login failures have reached maxinum, please try again in 10 minutes!")

Output:

1) Input correct username and password

please enter your username: Jack
please enter your password: 123a
login succeeded

2) Re-run the program with the input of wrong username and password for 3 times

please enter your username: Jack
please enter your password: 456b
login failed
please enter your username: Kate
please enter your password: 123a
login failed
please enter your username: Peter
please enter your password: 123a
login failed

Your login failures have reached the maximum, please try again in 10 minutes!