Probably a mess up on my part. Normally in PyDash, nth will return a None or your value. However, that’s not really helpful so we “lift” as they call it to a Maybe. I’ll check that section again, thanks for letting me know. In the meantime, just know that nth is a pure function and won’t blow up, whereas in normal Python code, accessing a List with an index that doesn’t exist results in an Exception. Using nth is safe, but downstream code may not be expecting a None and end up throwing an Exception by accident. Forcing it to be a Maybe ensures the downstream is then forced to handle the Nothing scenario.

Using the returns library, they have a wonderful decorator to make this easier:

@maybe
def safe_nth(index, list):
  return nth(index, list)

One example that I didn’t quite get was the one below “You’ll see this implemented in a more re-usable way as nth, except instead of returning None, it’ll return a Maybe” — it returns the same things as the previous example (modulo capitalization on “OK/Ok”). Is there some other code that’s supposed to be there?

Good point and that other article is a great read as well…

‘Cause I stupid and don’t proof read. Thanks for the catch! It should be:

def get_loan_ids_result():
  return get_kms_secret() \
  >> get_oauth_token \
  >> get_loan_ids