Implement --pdb in a python cli
===============================

Adding a flag to your applications can make them much easier for those using it to debug your application, especially if your applicatoin is a cli...

Date: January 13, 2022

Adding a `--pdb` flag to your applications can make them much easier for
those using it to debug your application, especially if your applicatoin
is a cli application where the user has much fewer options to start this
for themselves. To add a pdb flag `--pdb` to your applications you will
need to wrap your function call in a try/except, and start a post_mortem
debugger. I give credit to
[this stack overflow post](https://stackoverflow.com/questions/242485/starting-python-debugger-automatically-on-error)
for helping me figure this out.

``` python
import pdb, traceback, sys

def bombs():
 a = []
 print(a[0])

if __name__ == "__main__":
 if "--pdb" in sys.argv:
 try:
 bombs()
 except:
 extype, value, tb = sys.exc_info()
 traceback.print_exc()
 pdb.post_mortem(tb)
 else:
 bombs()
```

## Using --pdb

``` python
python yourfile.py --pdb
```

![running this example with and without --pdb flag](https://images.waylonwalker.com/using-pdb-flag-from-cli.png)