“Ask forgiveness not permission” - explain

Question

I\'m not asking for personal \"religious\" opinions about this philosophy, rather something a bit more technical.

I understand this phrase is one of several litmus t

Answer 1

Ask forgiveness not permission is meant to simplify code. It's meant for code to be written like this when there's a reasonable expectation that .bar might trigger an AttributeError.

 try:
     print foo.bar
 except AttributeError as e
     print "No Foo!" 

Your code appears to both ask permission AND forgiveness :)

The thing is, if you reasonably expect something to fail, use a try/catch. If you don't expect something to fail, and it fails anyway, well the exception that gets thrown becomes the equivalent of a failed assertion in other languages. You see where the unexpected exception is occurring and adjust your code/assumptions accordingly.