CODEWITHSUNDEEP
python
Jeremy
Jeremy

Reputation: 1675

How can I restrict to certain user inputs?

I am creating a password validation module,but I don´t know how can I put certain rules for said password. The password needs at least 1 uppercase letter, 1 lowercase letter and 1 number

Here´s what I have coded so far:

def validacion_contraseña():
    flag = 1
    import re
    while (flag == 1):
        cont = 0
        pass=input("Ingresa una contraseña:")
        # r = re.match("^[a-z]*$", usser)
        for x in pass:
            cont = cont + 1
        if (cont < 8):
            print(True)
            flag = 0
        if not (re.match("[aA-zZ,0-9]",pass)):
            print("El nombre de usuario puede contener solo letras y números.")
            flag = 0
        if (flag == 1):
            print(True)
            flag = 0

Upvotes: 1

Views: 198

Answers (1)

Basic
Basic

Reputation: 26766

First of all, don't use pass as a variable - it's a python keyword (which means "do nothing")...

def something():
    pass

Next, I'd suggest counting each class (nums/upper/lower) separately and then checking if they meet requirements.

Also note that you almost always want to import something only once. Except in some advanced cases, all import statements should be at the very top of the file.

Finally, let's use a boolean valid variable to tidy up the loop condition a bit...

import re

def validacion_contraseña():
    valid = False
    while not valid:
        contrasena = input("Ingresa una contraseña:")
        nums = len(re.findall('[0-9]', contrasena))
        lower = len(re.findall('[a-z]', contrasena))
        upper = len(re.findall('[A-Z]', contrasena))

        if nums >= 1 and lower >= 1 and upper >= 1:
            valid = True
    print('Contraseña: {0}' + contrasena)

We're using re.findall() to find every non-overlapping match to the pattern. For a 1-character pattern, this effectively returns a list of matching characters.

We then count the number of items returned using len().

Upvotes: 2

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