Are Django fields being used in my templates?

find_mode_fields_used_in_template_files.py

import os
from subprocess import check_output
from django.apps import apps

# Are my django model fields actually being used in my templates? This function lists the unused ones.
# Note - scans for *html and api.py (Django Rest Framework) files

def find_str(needle, full_path='/home/myacct/Projects/my_project/'):
    try:
        f = check_output(f'/bin/grep -nr  --include="*.html" "{needle}" ' + 
                         ' --include="api.py" '+
                         '{full_path}', 
                         shell=True                 
                        )
    except Exception as err:
        return False
    return True

def show_usages(app_to_scan):
    app_models = apps.get_app_config(app_to_scan).get_models()
    for model in app_models:
        print(model.__name__)
        print('-'* len(model.__name__))
        fields = model._meta.get_fields()
        for f in fields:
            fld = str(f).split('.')[-1:][0]
            if not find_str(fld):
                print(fld)
                
show_usages('product')