Utilizing Django url resolver vs. re-inventing the request.path parsing wheel - django

Question

Let's say I had the following array:
sub_urls = [
'/',
'/<uuid:id>',
'/test',
'/test/<uuid:id>'
]
The URL stings are very similar to what you'd find in Django's urlpatterns
my question:
can django.url.resolve be used to find the pattern in the sub_urls array given a path string like /test/189e8140-e587-4d5d-ac5c-517fd55c67bc without me having to re-invent the wheel here?
PLEASES NOTE: this isn't a question about how I route from urls to views in Django. Please don't tell me how to "solve it with urlpatterns, re_path etc." This is about utilizing this same mechanism by which django matches up a URL with a view --- for a COMPLETELY different purpose. I can write this myself, but I wanted to know if there's a way to re-use what Django has as it CLEARLY has the same needs when parsing request.path into the correct view.

Answer 1

Since django.urls.resolve calls get_resolver which creates a URLResolver (through _get_cached_resolver), you can instead create a URLResolver yourself:
# Define an empty view
def empty_view(*args, **kwargs):
return None
# Define the urlpatterns
from django.urls import path
sub_urls = [
'/',
'/<uuid:id>',
'/test',
'/test/<uuid:id>'
]
urlpatterns = [path(u, empty_view) for u in sub_urls]
# Create a resolver
from django.urls.resolvers import URLResolver, RegexPattern
resolver = URLResolver(RegexPattern(r'^'), urlpatterns)
# Match a path
# Returns a django.urls.resolvers.ResolverMatch object
result = resolver.resolve('/test/189e8140-e587-4d5d-ac5c-517fd55c67bc')
print(result)
print(result.route)
The above code will output:
ResolverMatch(func=__main__.empty_view, args=(), kwargs={'id': UUID('189e8140-e587-4d5d-ac5c-517fd55c67bc')}, url_name=None, app_names=[], namespaces=[], route=/test/<uuid:id>)
/test/<uuid:id>
If you're set on using django.urls.resolve, you could move urlpatterns to a module, let's say my_urls:
# Define an empty view
def empty_view(*args, **kwargs):
return None
# Define the urlpatterns
from django.urls import path
sub_urls = [
'',
'<uuid:id>',
'test',
'test/<uuid:id>'
]
urlpatterns = [path(u, empty_view) for u in sub_urls]
Notice we had to remove the / suffixes from the URLs above because _get_cached_resolver creates a RegexPattern that starts with /.
And then pass the module name as the second argument to resolve:
# Configure settings (only needed when this is not being run in an existing Django app)
from django.conf import settings
settings.configure()
# Match a path
# Returns a django.urls.resolvers.ResolverMatch object
from django.urls import resolve
result = resolve('/test/189e8140-e587-4d5d-ac5c-517fd55c67bc', urlconf='my_urls')
print(result)
print(result.route)
I don't believe the caching of _get_cached_resolver should be an issue as #Clepsyd mentioned since functools.lru_cache caches depending on the arguments it receives.