Django - Adding password validations in a ModelForm

Question

I have made a ModelForm in Django for the registration of a new user. It has 4 fields (username, email, password, and confirm_password). I want to add some validations for the password field. For example, if the password is shorter than 8 characters or the password is similar to the username, then raise an error message. How can I do this?

Here is my forms.py file:

from django.contrib.auth.models import User
from django import forms

class user_form(forms.ModelForm):
    password = forms.CharField(widget = forms.PasswordInput)
    confirm_password = forms.CharField(widget = forms.PasswordInput)

    class Meta:
        model = User
        fields = ['username','email', 'password','confirm_password']

My settings.py already contains the following validators:

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimila‌​rityValidator', 
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValida‌​tor',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValid‌​ator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordVali‌​dator',
    }
]

It's already in settings.py, but my form's password is not being validated.

Answer 1

in forms.py file you can use this to validate the password for all validations which have been defined in settings. if you didn't define any of the validators in the settings file then call a specific validator which you want to validate.

from django.contrib.auth.password_validation import validate_password`
from django.core import validators
from django import forms
class User_profileForm(forms.ModelForm):
password=forms.CharField(widget=forms.PasswordInput,validators=[validate_password])