Python tarfile 比 Linux 命令慢

Question

我尝试了不同的压缩文件夹的方法。我的理解是 Python 内置模块总是比 subprocess.call("Linux command") 快。但我只是做了一些演示。tarfile 模块比 subprocess.call("tar") 慢。有人可以向我解释一下吗？

    #!/usr/bin/python

import os
import time
import tarfile
import subprocess

tStart1 = time.time()

TestFolder = ["Jack", "Robin"]
for folder in TestFolder:
    name = "/mnt/ShareDrive/Share/ExistingUsers/"+folder
    path = "/mnt/TEST2/"
    tar = tarfile.open(path+folder+".tar.gz", "w:gz")
    tar.add(name)
    tar.close()
tEnd1 = time.time()

time.sleep(2)

tStart2 = time.time()
for folder in TestFolder:
    path = "/mnt/TEST1/"
    subprocess.call(["tar", "zcvf", path+folder+".tar.gz", "-P", "/mnt/ShareDrive/Share/ExistingUsers/"+folder])
tEnd2 = time.time()

print "The module cost %f sec" % (tEnd1 - tStart1)
print "The subprocess cost %f sec" % (tEnd2 - tStart2)

tarfile 模块花费 63 秒。子流程仅花费 32 秒。

两个文件夹的总大小为 433 MB

Answer 1

tar用 C 编写。该tarfile模块是 tar 处理的纯 Python 实现。模块不可能比命令更快。