#!/usr/bin/env python3
 
import timeit
 
def f():
    buf = b""
 
    for i in range(20480):
        buf += b'c'
 
    return buf
 
def g():
    buf = bytearray()
 
    val = b'c'[0]
 
    for i in range(20480):
        buf.append(val)
 
    return bytes(buf)
 
def h():
    buf = [] 
 
    for i in range(20480):
        buf.append(b'c')
 
    return b"".join(buf)
 
def j():
    def inner():
        for i in range(20480):
            yield b'c'
 
    return b"".join(inner())
 
if __name__ == "__main__":
    print(timeit.repeat(f, number=3))
    print(timeit.repeat(g, number=3))
    print(timeit.repeat(h, number=3))
    print(timeit.repeat(j, number=3))

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