Making a Regex Django URL Token Optional

Question

You have a URL which accepts a first_name and last_name in Django:

('^(?P<first_name>[a-zA-Z]+)/(?P<last_name>[a-zA-Z]+)/$','some_method'),

How would you include the OPTIONAL URL token of title, without creating any new lines. What I mean by this is, in an ideal scenario:

#A regex constant
OP_REGEX = r'THIS IS OPTIONAL<title>[a-z]'
#Ideal URL
('^(?P<first_name>[a-zA-Z]+)/(?P<last_name>[a-zA-Z]+)/OP_REGEX/$','some_method'),

Is this possible without creating a new line i.e.

('^(?P<first_name>[a-zA-Z]+)/(?P<last_name>[a-zA-Z]+)/(?P<title>[a-zA-Z]+)/$','some_method'),

Solution 1

('^(?P<first_name>[a-zA-Z]+)/(?P<last_name>[a-zA-Z]+)(?:/(?P<title>[a-zA-Z]+))?/$','some_method'),

Don't forget to give title a default value in the view.

Solution 2

In case your are looking for multiple optional arguments, without any required ones, just omit "/" at the beginning, such as:

re_path(r'^view(?:/(?P<dummy1>[a-zA-Z]+))?(?:/(?P<dummy2>[a-zA-Z]+))?(?:/(?P<dummy3>[a-zA-Z]+))?/$', views.MyView.as_view(), name='myname'),

which you can browse at:

http://localhost:8000/view/?dummy1=value1&dummy2=value2&dummy3=value3

Comments

[Federer]

thanks for that. How would I make a URL of JUST optional 'titles'? i.e. (?:/(?P<title1>[a-zA-Z]+))?(?:/(?P<title2>[a-zA-Z]+))? thanks for any help

[Chris]

Note that the ?: is important in the outer group. Without it, the URL will work properly when navigated to, but reverse() won't notice the argument inside.

[srus]

More info about this in the official docs.