Python将byte数组转换为int，pythonbyte数组int,代码```pythoni

Python将byte数组转换为int，pythonbyte数组int,代码```pythoni

代码```pythonimport structimport ctypes

def test_struct(buf, offset): return struct.unpack_from("I", buf, offset)[0]

def test_ctypes(buf, offset): return ctypes.c_uint32.from_buffer(buf, offset).value

def test_multi(buf, offset): return buf[offset] + (buf[offset+1] << 8) + (buf[offset+2] << 16) +(buf[offset+3] << 24)

buf_w = bytearray(5)buf_w[1] = 1buf_r = buffer(buf_w)

if name == 'main': import timeit t1 = timeit.Timer("test_struct(buf_r, 1)", "from main import test_struct, buf_r") t2 = timeit.Timer("test_ctypes(buf_w, 1)", "from main import test_ctypes, buf_w") t3 = timeit.Timer("test_multi(buf_w, 1)", "from main import test_multi, buf_w") print t1.timeit(number=1000) print t2.timeit(number=1000) print t3.timeit(number=1000)

 结果 ```pythonnumber = 100000.00819587707520.0125491619110.0112121105194number = 10000.000873088836670.001257896423340.00110197067261number = 1000.0000917911529541     # 9.17911529541e-050.0001339912414550.00011420249939number = 101.69277191162e-052.19345092773e-051.69277191162e-05number = 11.00135803223e-051.00135803223e-055.96046447754e-06