[gamegoblin]

Interestingly enough, this is pretty much the example given for the timemit module:

http://docs.python.org/2/library/timeit.html

Results:

    $ python -m timeit '"-".join(str(n) for n in range(100))'

    10000 loops, best of 3: 40.3 usec per loop

    $ python -m timeit '"-".join([str(n) for n in range(100)])'

    10000 loops, best of 3: 33.4 usec per loop

    $ python -m timeit '"-".join(map(str, range(100)))'

    10000 loops, best of 3: 25.2 usec per loop

[dbarlett]

I just ran those with Python 2.7 (ASCII and Unicode) and Python 3.2 (Unicode). "-".join(map(str, range(100))) was always the fastest, with ASCII (2.7) < Unicode (3.2) < Unicode (2.7). Makes sense, but worth keeping in mind when porting code from Python 2 to 3.

Full results: https://gist.github.com/dbarlett/6479378