Copy binary file by using buffer

buffer_size = 100000

input = open('leafs.jpg', 'rb')
output = open('leafs_01.jpg', 'wb')

buffer = input.read(buffer_size)

while len(buffer) > 0:
    output.write(buffer)
    print('.', end='')
    buffer = input.read(buffer_size)

input.close()
output.close()