Question

I have a form field:

web_address = forms.RegexField(regex=r'^DO SOMETHING$', error_messages = {'invalid': _("Not a valid web address.")})

I am unable to write a regular expression for the above address. My requirement is to validate the url in the form http://maps.google.com/maps/place?cid=1234. The id 1234 is a variant but the prior would be constant.

Please help!!!

Answer 1

There are just two thing to know

1. ? and . are special characters in regex and need escaping
2. checking for digits, either use the predefined class \d or define your own [0-9] and say at least one \d+

so your regex should look something like

^http://maps\.google\.com/maps/place\?cid=\d+$

If you want to learn more about regexes, http://www.regular-expressions.info is a good place to start.

To test you regexes you can use online testers like gskinner.com/RegExr/. You can see your regex here