How to prevent usernames from containing @/./+/-/_.?

Question

I\'m using django-allauth, and for some reason the username default allows:

\"letters, digits and @/./+/-/_.\"

How can I ensure usernames are strictly alphanumer

Answer 1

I think python's builtin function str.isalnum() could be usefull here.

class UsernameMaxAdapter(DefaultAccountAdapter):
    def clean_username(self, username):
        # assumes "username" is a type of "str" object
        if not username.isalnum():
            raise ValidationError("Use only alphanumeric characters")
        # your logic

UPDATE-1
set ACCOUNT_USERNAME_VALIDATORS in settings.py as mentioned in documentation

class CustomValidator(object):

    def __call__(self, username="", *args, **kwargs):
        username = username.isalnum()
        if not username:
            raise ValidationError("Use only alphanumeric characters")

in your settings.py,

custom_username_validators = [CustomValidator()]
ACCOUNT_USERNAME_VALIDATORS = 'path.to.settings.custom_username_validators'