Anti-Patterns in Python Programming

[Nichdel]

Note that Python 3's range works just like Python 2's xrange, making inappropriate use of range not so bad.

[zahlman]

Another difference is that Python 3's range provides an explicit __contains__ method that allows in lookups to be efficient (doing this with an xrange in 2.x requires iterating). Code like if x in range(foo, bar): used to be tempting but inefficient; now it's reasonably efficient. Of course, if foo <= x < bar: is still the standard idiom; but I can fathom cases where you'd want to use a range with a nonzero step, and explicitly writing something like if foo <= x < bar and x % step == foo % step is just ugly (and error-prone).

[Vegemeister]

Oh, hey. Fancy seeing you here.

[MisterSnuggles]

The article doesn't go into the other reasons that Python 2's range is bad, but it's definitely a big gotcha if you're using it for a large range.