Raise exception vs. return None in functions?

Question

What\'s better practice in a user-defined function in Python: raise an exception or return None? For example, I have a function that finds the mos

Answer 1

I would make a couple suggestions before answering your question as it may answer the question for you.

• Always name your functions descriptive. latestpdf means very little to anyone but looking over your function latestpdf() gets the latest pdf. I would suggest that you name it getLatestPdfFromFolder(folder).

As soon as I did this it became clear what it should return.. If there isn't a pdf raise an exception. But wait there more..

• Keep the functions clearly defined. Since it's not apparent what somefuc is supposed to do and it's not (apparently) obvious how it relates to getting the latest pdf I would suggest you move it out. This makes the code much more readable.

---

for folder in folders:
   try:
       latest = getLatestPdfFromFolder(folder)
       results = somefuc(latest)
   except IOError: pass

Hope this helps!