I posted recently that I had started on Bites of Py Exercises, and i’m glad to say I have finished a few more. Small wins are good!
Along the way i’ve discovered, thanks again to the Python Bytes podcast, a new way to see crashes in my scripts. Currently I am working slowly towards scraping my favorite wallpapers from wallhaven.cc and downloading them. But, as I mention in the title, I seem to be better at writing bugs than functional code.
When a script crashes in Python you get a traceback, which seems to be a backwards listing of the things that caused the crash. With practice I will get better at making sense of things like this:
Traceback (most recent call last):
File "wff-selenium-no-login.py", line 6, in
from urllib import Request
ImportError: cannot import name 'Request' from 'urllib' NameError: name 'Request' is not defined
File "wff-selenium-no-login.py", line 24, in
req = request(wallpaper, headers = {"User-Agent": "Mozilla/5.0"})
TypeError: 'module' object is not callable
But thanks to that episode I learned about friendly_traceback, which gives me this output instead:
Python exception:
TypeError: 'module' object is not callable
A TypeError is usually caused by trying to combine two incompatible types of objects, by calling a function with the wrong type of object,
or by tring to do an operation not allowed on a given type of object.
Execution stopped on line 24 of file 'wff-selenium-no-login.py'.
-->24: req = request(wallpaper, headers = {"User-Agent": "Mozilla/5.0"})
request: <module 'urllib.request' from '/Users/davidr/...>How is this better? Well.. it explains the error, points to the line I need to fix.. and also tells me the module I have issue with. Though I still don’t know what to do to fix it it makes me feel like I have a better handle on it.