how to create a login page in python

1CorrectUsername = surname[0:3] + firstname[0:3]
2
3loop = 'true'
4while (loop == 'true'):
5    username = input("Please enter your username: ")
6    if (username == CorrectUsername):
7    	password = input("Please enter your password: ")
8        if (password == CorrectPassword):
9            print("Logged in successfully as ") + username
10            loop = 'false'
11        else:
12            print "Password incorrect!"
13    else:
14        print "Username incorrect!"

1{% extends 'main/header.html' %}
2
3{% block content %}
4
5    <div class="container">
6        <form method="POST">
7        {% csrf_token %}
8        {{form.as_p}}
9            <button style="background-color:#F4EB16; color:blue" class="btn btn-outline-info" type="submit">Login</button>
10        </form>
11        Don't have an account? <a href="/register" target="blank"><strong>register here</strong></a>!
12    </div>
13{% endblock %}

1while (loop == 'true'):
2    username = input("Please enter your username: ")
3    if (username == CorrectUsername):
4    	password = input("Please enter your password: ")
5        if (password == CorrectPassword):
6            print("Logged in successfully as ") + username
7            loop = 'false'
8        else:
9            print "Password incorrect!"
10    else:
11        print "Username incorrect!"

1sum = 10
2sum1 = 20
3print(sum+sum1)