Building Web Applications with Flask

coding:utf-8
from wtforms import Form, ValidationError
from wtforms import StringField, PasswordField
from wtforms.validators import Length, InputRequired
from werkzeug.datastructures import MultiDict
import re
def is_proper_username(form, field):
if not re.match(r"^\w+$", field.data):
msg = '%s should have any of these characters only: a-z0-9_' % field.name
raise ValidationError(msg)
class LoginForm(Form):
username = StringField(
u'Username:', [InputRequired(), is_proper_username, Length(min=3, max=40)])
password = PasswordField(
u'Password:', [InputRequired(), Length(min=5, max=12)])
@staticmethod
def validate_password(form, field):
data = field.data
if not re.findall('.*[a-z].*', data):
msg = '%s should have at least one lowercase character' % field.name
raise ValidationError(msg)
# has at least one uppercase character
if not re.findall('.*[A-Z].*', data):
msg = '%s should have at least one uppercase character' % field.name
raise ValidationError(msg)
# has at least one number
if not re.findall('.*[0-9].*', data):
msg = '%s should have at least one number' % field.name
raise ValidationError(msg)
# has at least one special character
if not re.findall('.*[^ a-zA-Z0-9].*', data):
msg = '%s should have at least one special character' % field.name
raise ValidationError(msg)
# testing our form
form = LoginForm(MultiDict([('username', 'italomaia'), ('password', 'lL2m@msbb')]))
print form.validate()
print form.errors