time performance: string.join vs. string.__add__

join_vs_plus.py

#!/usr/bin/env python
from profilestats import profile # $ pip install profilestats

def join_join(a, b):
    return ','.join([a, b])

def join_plus(a, b):
    return a + ',' + b

@profile
def test():
    N = 10**4
    for a, b in generate_str_pairs(N):
        assert join_plus(a, b) == join_join(a, b)
    for a, b in generate_str_pairs(N):
        assert join_join(a, b) == join_plus(a, b)

def generate_str_pairs(n):
    for i in xrange(n):
        yield 'a'*i, 'b'*i

if __name__ == "__main__":
    test()