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Triggering the debugger on purpose

By Dag Odenhall filed in Utilities

The Flask (Werkzeug) debugger is really good, but it only triggers on exceptions — sometimes it could be useful for debugging behavior that isn't raising anything. In these situations you can simply raise an exception intentionally.

@app.route('/')
def index():
   do_something_wrong()
   raise
   return 'Ohnoes'

This use of raise is actually wrong, which means it… raises an exception. ☺

If you're afraid you might accidentally leave this in the code, here's one that only enters the debugger in debug-mode:

assert app.debug == False

This snippet by Dag Odenhall can be used freely for anything you like. Consider it public domain.

Comments

Division zero abusing by Armin Ronacher on 2010-05-26 @ 15:46
My classic:
```
1/0
```
Put it in a function by Dag Odenhall on 2010-05-27 @ 02:46
```
from flask import current_app

def debug():
    assert current_app.debug == False
```
Now you can trigger the debugger with debug().
Give yourself a message by Ron DuPlain on 2011-01-15 @ 22:52
The function from Dag above is great. I'll extend it slightly to add a friendly reminder message that you're seeing the debugger because you requested it.
```
from flask import current_app

def debug():
    assert current_app.debug == False, "Don't panic! You're here by request of debug()"
```