When performing the db_populate command, an error occurs even though I've just installed all dependencies.
Solved the issue by doing:
pip install pytz

I'd recommend adding the pytz package to the requirements.txt file.

http://127.0.0.1:8000/admin/statistics/ - new admin view
Followed your wonderful tutorial and came across an issue with this particular view. It doesn't show admin/statistics.html page instead gives 404 error.

Page not found (404)
Request Method: | GET
Request URL: http://127.0.0.1:8000/admin/statistics
Raised by: django.contrib.admin.sites.catch_all_view

Using the URLconf defined in core.urls, Django tried these URL patterns, in this order:
admin/ [name='index']
admin/ login/ [name='login']
admin/ logout/ [name='logout']
admin/ password_change/ [name='password_change']
admin/ password_change/done/ [name='password_change_done']
admin/ autocomplete/ [name='autocomplete']
admin/ jsi18n/ [name='jsi18n']
admin/ r/int:content_type_id/path:object_id/ [name='view_on_site']
admin/ auth/group/
admin/ auth/user/
admin/ shop/item/
admin/ shop/purchase/
admin/ ^(?P<app_label>auth|shop)/$ [name='app_list']
admin/ (?P.*)$

The current path, admin/statistics, matched the last one.