Comparison with False - something I don't understand

[Martin v. Loewis]

> result = myfunction (vars) 
> 
> if not result:
>     # error condition
> 
> Now above I first realized that the function can also return an empty 
> list under some conditions and so changed it to

If your function returns a list when successful, it should not return
False in the error case. Instead, it should return None (indicating that
there is no list).

Then the condition changes to

result = myfunction()
if result is None:
  # error condition

Using None for "no result available" is very common in Python. Using
False for the same purpose (i.e. returning either a list or False)
is not. If you return False from a function, the only other possible
result should be True.

Regards,
Martin