def password_validator(self, form, field):
        """Ensure that passwords have at least 6 characters with one lowercase letter, one uppercase letter and one number.

        Override this method to customize the password validator.
        """

        # Convert string to list of characters
        password = list(field.data)
        password_length = len(password)

        # Count lowercase, uppercase and numbers
        lowers = uppers = digits = 0
        for ch in password:
            if ch.islower(): lowers += 1
            if ch.isupper(): uppers += 1
            if ch.isdigit(): digits += 1

        # Password must have one lowercase letter, one uppercase letter and one digit
        is_valid = password_length >= 6 and lowers and uppers and digits
        if not is_valid:
            raise ValidationError(
                _('Password must have at least 6 characters with one lowercase letter, one uppercase letter and one number'))
def password_validator ( self , form , field ) : password = list ( field . data ) password_length = len ( password ) lowers = uppers = digits = 0 for ch in password : if ch . islower ( ) : lowers += 1 if ch . isupper ( ) : uppers += 1 if ch . isdigit ( ) : digits += 1 is_valid = password_length >= 6 and lowers and uppers and digits if not is_valid : raise ValidationError ( _ ( 'Password must have at least 6 characters with one lowercase letter, one uppercase letter and one number' ) )
Ensure that passwords have at least 6 characters with one lowercase letter, one uppercase letter and one number.

        Override this method to customize the password validator.