title: Login from textfile in python
body: <p>I'm trying to create a user login in python. Creating an account works but when trying to be an existing user it doesn't work.
  This is the code for that section:</p>
  
  <pre><code>elif login == "existing":
          un = input("Username: ")
          pw = input("Password: ") 
          f = file = open(un + ".txt", "r")
          if(file.readline())== ('Username: ' + un):
              print("Welcome")
          elif(file.readline())!= ("Password: ",pw): 
              print("Incorrect username or password.")
              un = input("Username:") 
              pw = input("Password:") 
              text_file = open(un + ".txt", "r")
              un = input("Username:") 
              pw = input("Password:")
              f = file = open(un +".txt", "r")
              print('Incorrect, closing the program.')
              Menuv2.close()
          else:
              print('Invalid input.')
              'Menuv2.py'.close()
  </code></pre>
  
  <p>It doesn't print welcome even when the username and password is correct. Any ideas?</p>