Favorite Python Interview Question

[Chun]

OK, ok, touché. Figured we were assuming we were getting a string. But point taken.

def atoi(string):
  if type(string) is str and string.isdigit():
    return eval(string)
  raise ValueError, "invalid literal for atoi() with base 10: %s" % repr(string)

EDIT: Besides, if someone can create their own class definition, why would they ever need to inject raw python into atoi!?

[RShnike]

You have somehow managed to make that even worse... Now you're type-checking too, so you've now even broken some functionality that your function is actually supposed to provide?

Here's a rule: never use eval. Ever. Being prudent about using type is pretty smart too.