How to avoid url looping in django?

Question

Django

Hello! I have a 'shop' button on my site, and a 'back' button in the shop. And if you need to go back (from the store), then this code executes.

urlpatterns = [
    url(r'^$', views.index, name='index'),
    url(r'^list.html/$', views.product_list, name = 'product_list'),
    url(r'^list.html/index.html/$', views.index, name = 'index'),
]

but as you can understand, the url is simply summed up and does not work normally with it.
Here's an example:
' localhost:8000/list.html/index.html/list.html '
And I just can't figure out how to avoid it.
Thank you!