Best way to loop over a python string backwards

Question

What is the best way to loop over a python string backwards?

The following seems a little awkward for all the need of -1 offset:

string = \"trick or          


        

Answer 1

Yes, the second syntax shortcut creates an intermediate string and has an associated performance penalty.

The first version is better written as:

for index, char in enumerate(reversed(s)):
   print "pos %d: %s" % (index, char)

Which is easy to comprehend. Neither reversed nor enumerate` need to make a copy of the string.

Also be careful about using string as a variable name, as it is also the name of a module in the standard library.