python_string_concat.sh

$ cat /proc/cpuinfo | grep "model name" | uniq
model name	: Intel(R) Core(TM)2 Quad CPU    Q8400  @ 2.66GHz
$ uname -a
Linux Q8400 3.5.0-37-generic #58-Ubuntu SMP Mon Jul 8 22:07:55 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

$ python --version
Python 2.7.3

$ python -m timeit '"-".join(str(n) for n in range(100))'
10000 loops, best of 3: 24.4 usec per loop
$ python -m timeit '"-".join([str(n) for n in range(100)])'
10000 loops, best of 3: 20.6 usec per loop
$ python -m timeit '"-".join(map(str, range(100)))'
100000 loops, best of 3: 15.9 usec per loop

$ python -m timeit 'u"-".join(str(n) for n in range(100))'
10000 loops, best of 3: 34.5 usec per loop
$ python -m timeit 'u"-".join([str(n) for n in range(100)])'
10000 loops, best of 3: 29.5 usec per loop
$ python -m timeit 'u"-".join(map(str, range(100)))'
10000 loops, best of 3: 24.3 usec per loop

$ python3 --version
Python 3.2.3

$ python3 -m timeit '"-".join(str(n) for n in range(100))'
10000 loops, best of 3: 29.9 usec per loop
$ python3 -m timeit '"-".join([str(n) for n in range(100)])'
10000 loops, best of 3: 25.8 usec per loop
$ python3 -m timeit '"-".join(map(str, range(100)))'
100000 loops, best of 3: 19 usec per loop