Python 2.x gotchas and landmines

Question

The purpose of my question is to strengthen my knowledge base with Python and get a better picture of it, which includes knowing its faults and surprises. To keep things sp

Answer 1

There was a lot of discussion on hidden language features a while back: hidden-features-of-python. Where some pitfalls were mentioned (and some of the good stuff too).

Also you might want to check out Python Warts.

But for me, integer division's a gotcha:

>>> 5/2
2

You probably wanted:

>>> 5*1.0/2
2.5

If you really want this (C-like) behaviour, you should write:

>>> 5//2
2

As that will work with floats too (and it will work when you eventually go to Python 3):

>>> 5*1.0//2
2.0

GvR explains how integer division came to work how it does on the history of Python.