It seems that subject might be None in some cases, causing the error "Reverse for 'course_listsubject' with arguments '('',)' not found. 1 pattern(s) tried: ['course/subject/(?P[-a-zA-Z0-9]+)/\Z']"
when trying to reverse the URL.
Suggested improvement in this case is by checking if subject is not None before attempting to access its attributes.
It seems that subject might be None in some cases, causing the error "Reverse for 'course_listsubject' with arguments '('',)' not found. 1 pattern(s) tried: ['course/subject/(?P[-a-zA-Z0-9 ]+)/\Z']"
when trying to reverse the URL.
Suggested improvement in this case is by checking if subject is not None before attempting to access its attributes.