在Django中，当我不知道在哪里设置跟踪时，如何触发pdb找出导致404错误的原因？

Question

In my Django app, I'm getting a 404 Page Not Found response that looks like it's being caused by some logic in one of my custom template tags -- but I don't know which one.

Using Django Debug Toolbar's Request Vars panel, I can see the view causing the 404 is go_back.utils._register_wrapped_view -- which is how I know it's coming from one of my go_back.utils template tags.

Unfortunately, because template tags need to be decorated and thus show up as _registered_wrapped_view , I can't tell which tag it is, much less where in the tag code the problem happens. (The tag code is a special utility which works with urls and calls resolve in several places so it's not obvious.)

Thus I can't use the normal import pdb; pdb.set_trace() import pdb; pdb.set_trace() approach because I don't know where to set the trace.

So how can I get pdb to break when the 404 happens so I can see the stack trace leading to that point?

Answer 1

Try using the Django Debug Toolbar , it can intercept redirects, good for when you cant find where to add a breakpoint.

In settings make sure you have

DEBUG_TOOLBAR_CONFIG = {'INTERCEPT_REDIRECTS': True}

Answer 2

Old question, but there is django-pdb which has a post mortem flag for runserver. It doesn't look well maintained (2 years ago is the last commit), but it is simple middleware and updating it shouldn't be too hard.

Answer 3

I'm not sure if you know this:

You can try putting import pdb; pdb.set_trace() import pdb; pdb.set_trace() in the function which you want to debug and development server. When that function triggers it will break into pdb shell and you can debug your code.