django form validators

validators.py

# coding:utf-8
from django import forms
from django.core.validators import RegexValidator
from datetime import datetime
import re


def only_character_number_underline(value):
    RegexValidator(regex=r'^[A-Za-z0-9_]+$', message='only number, A-Z, a-z, _')(value)


def only_character_number(value):
    RegexValidator(regex=r'^[A-Za-z0-9]+$', message='only number, A-Z, a-z')(value)


def only_32_hexadecimal_characters(value):
    RegexValidator(regex=re.compile('[0-9a-f]{32}\Z', re.I), message='not exactly 32 hexadecimal characters')(value)


def validate_date(value):
    try:
        datetime.strptime(value, '%Y-%m-%d')
    except Exception as ex:
        raise forms.ValidationError(ex)


def validate_iso_date(value):
    validate_date(value)
    d = datetime.strptime(value, '%Y-%m-%d')
    if str(value) != d.date().isoformat():
        raise forms.ValidationError('date not iso format date')


def validate_week_U(value):
    '''
    Week number of the year (Sunday as the first day of the week) as a zero padded decimal number. All days in a new year preceding the first Sunday are considered to be in week 0.
    '''
    try:
        datetime.strptime(value, '%Y-%U')
    except Exception as ex:
        raise forms.ValidationError(ex)


def validate_week_perfix_for_zero(value):
    validate_week_U(value)
    try:
        _ww = str(value)[5:]         # yyyy-ww ==> ww
        if int(_ww) < 10 and _ww[0] != '0':
            raise forms.ValidationError('week perfix for zero, {} ==> {}-0{}'.format(value, value[:4], _ww))
    except Exception as ex:
        raise forms.ValidationError(ex)


def validate_month(value):
    '''
    Month as a zero-padded decimal number.
    Example: 01, 02, ..., 12
    '''
    try:
        datetime.strptime(value, '%Y-%m')
    except Exception as ex:
        raise forms.ValidationError(ex)


def validate_month_prefix_for_zero(value):
    '''
    Month as a zero-padded decimal number.
    Example: 01, 02, ..., 12
    '''
    validate_month(value)
    try:
        _mm = str(value)[5:]         # yyyy-mm ==> mm
        if int(_mm) < 10 and _mm[0] != '0':
            raise forms.ValidationError('month perfix for zero, {} ==> {}-0{}'.format(value, value[:4], _mm))
    except Exception as ex:
        raise forms.ValidationError(ex)


def validate_period(value):
    _p = str(value)
    if _p not in ('day', 'week', 'month'):
        raise forms.ValidationError('''period not in ('day', 'week', 'month')''')


def validate_key(value):
    _k = str(value)
    if _k not in ('J', 'W'):
        raise forms.ValidationError('''key not in ('J', 'W')''')


def validate_unit(value):
    _u = str(value)
    if _u not in ('DAYS', 'MONTHS'):
        raise forms.ValidationError('''unit not in ('DAYS', 'MONTHS')''')

regex reference , http://blog.sina.com.cn/s/blog_887d00920100tvvd.html