How to put limitation on url patterns in Django 2

Question

Django 1.11 uses regular expression to check for appropriate url. eg

url(r'^(?P<year>[0-9]{4})/$', views.abc),

Here I could check that my year is 4 digits.

The new way introduced is like

path('<int:year>/', views.abc),

Is there a default way to use restrictions using path()?

Answer 1

Directly lifted from the Django Docs

You can define your custom converters:

class FourDigitYearConverter:
    regex = '[0-9]{4}'

    def to_python(self, value):
        return int(value)

    def to_url(self, value):
        return '%04d' % value

Then:

from django.urls import register_converter, path

from . import converters, views

register_converter(converters.FourDigitYearConverter, 'yyyy')

urlpatterns = [
    path('articles/2003/', views.special_case_2003),
    path('articles/<yyyy:year>/', views.year_archive),
    ...
]