PYTHON 复制文件的进度条程序

最近在学习PYTHON的多线程操作,写个复制文件带进度条的小程序玩,使用的是threading模块中类方法的多线程方式.linux系统中的cp命令与PYTHON的shutil模块都会导致复制大文件时高负载,处理大文件时感觉还需要再优化下程序.

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
from __future__ import division
import threading
import time
import os
import sys
#date = time.strftime('%Y%m%d')
class A(threading.Thread):
        def __init__(self):
                threading.Thread.__init__(self)
        def run(self):
                os.system("cp test.txt test.txt.1")
class B(threading.Thread):
        def __init__(self):
                threading.Thread.__init__(self)
        def run(self):
                global x
                global y
                x = 0
                if os.path.isfile("test.txt"):
                        y = os.stat("test.txt")[6]
                while x < y:
                        if os.path.isfile("test.txt.1"):
                                x = os.stat("test.txt.1")[6]
                        else:
                                #print 1
                                x = os.stat("test.txt.1")[6]
                        b = 0
                        a = int((x / y) * 100)
                        b = int(a - b)
                        j = '#' * int(b / 2)
                        sys.stdout.write(str(a)+"% ||"+j+"||"+"\r")
                        sys.stdout.flush()
                        time.sleep(2)
                print
def test():
        threadone = A()
        threadtwo = B()
        threadone.start()
        time.sleep(1)
        threadtwo.start()
if __name__ == '__main__':
        test()