import timeit, gc, sys
size = 100000
repeats = 10
numbers = 100
gc.disable()

def bench(a, b, c):
    for i in list(range(1, 11)) + [20, 50, 100, 1000, 10000]:
        string = (c * (i - 1) + a) * (size // i)
        string += c * (size - len(string))
        gc.collect()
        best = min(timeit.Timer("text.replace(a, b)",
                "a=%r; b=%r; text=%r" % (a, b, string)
            ).repeat(repeats, numbers))
        print('%.0f\t%d %a %a %a' % (best *1e6 / numbers, i, a, b, c))
        sys.stdout.flush()

bench('a', 'b', 'c')
bench('\u010a', '\u010b', '\u010c')
bench('\U0001000a', '\U0001000b', '\U0001000c')