Question

Without using reversed(), how would I loop a set of strings in Python in a function?

Stumbled upon ranges like:

range() and xrange() take a third parameter that specifies a step. So
you can do the following.

range(10, 0, -1) Which gives

[10, 9, 8, 7, 6, 5, 4, 3, 2, 1] But for iteration, you should really
be using xrange instead. So,

xrange(10, 0, -1)

But these don’t really speak to strings?

Answer 1

The function you’re looking for is list comprehensions. These are useful in that you don’t have to iterate over a sequence, which is what range and xrange (in 2.x) provide.

str can be iterated over and sliced, much like strings. The only difference is that str elements are immutable.

To your example, say you have a set of strings and you want to iterate over them. No problem – just remember that sets have no inherent ordering to them; they only guarantee that the contents are unique.

myset = set(["first", "second", "third", "fourth", "fifth"])
for i in myset:
    print i

…which prints:

second
fifth
fourth
third
first

It’s also the case that you can reverse a single string by itself using the step parameter for a sequence type, of which str belongs. You can do that with this:

"this is the song that never ends"[::-1]

…which prints:

'sdne reven taht gnos eht si siht'