python - jinja2.exceptions.UndefinedError: 'base' is undefined

Question

I am working on the Flask tutorial,try to create 404 by meself,but it keeps saying that 'base' is undefined.Here is the biaodan.py enter image description here

here is the base.html enter image description here

enter image description here

Here is the 404.htmlenter image description here

question from:https://stackoverflow.com/questions/65869731/jinja2-exceptions-undefinederror-base-is-undefined

Answer 1

Waitting for answers