#!/usr/bin/env python3

import timeit

def f():
    buf = b""

    for i in range(102400):
        buf += b'c'

    return buf

def g():
    buf = bytearray()

    for i in range(102400):
        buf.append(b'c'[0])

    return bytes(buf)

if __name__ == "__main__":
    print(timeit.repeat(f, number=2))
    print(timeit.repeat(g, number=2))