python 复制文件

import os,sys
maxfileload =10000000
blksize = 1024*500

def copyfile(pathFrom,pathTo,maxfileload=maxfileload):
    '''
    将单个文件逐字节从pathFrom复制到pathTo；
    使用二进制文件模式阻止Unicode解码及换行符转换。
    '''
    if os.path.getsize(pathFrom) <= maxfileload:
        bytesFrom = open(pathFrom,'rb').read()
        open(pathTo,'wb').write(bytesFrom)
    else:
        fileForm = open(pathFrom,'rb')
        fileTo = open(pathTo,'wb')
        while True:
            bytesFrom = fileForm.read(blksize)
            if not bytesFrom:break
            fileTo.write(bytesFrom)


def copyTree(dirFrom,dirTo,verbose=0):
    '''
    将dirFrom下的内容复制到dirTo，返回文件目录，数目形式的元祖；
    为避免在某些平台上目录名不可解码，可能需要为其名使用字节；
    在Unix下可能需要更多文件类型检查：跳过链接，fifo之类。
    '''
    fcount = dcount = 0
    for filename in os.listdir(dirFrom):
        pathFrom = os.path.join(dirFrom,filename)
        pathTo = os.path.join(dirTo,filename)
        if not os.path.isdir(pathFrom):
            try:
                if verbose>=1:print('copying',pathFrom,'to',pathTo)
                copyfile(pathFrom,pathTo)
                fcount += 1
            except:
                print("复制出错,从",pathFrom,'到',pathTo )
                print(sys.exc_info()[0],sys.exc_info()[1])
        else:
            if verbose: print('复制目录',pathFrom,'到',pathTo)
            try:
                os.mkdir(pathTo)
                below = copyTree(pathFrom,pathTo)
                fcount +=below[0]
                dcount +=below[1]
                dcount +=1
            except:
                print("复制出错",pathTo,'---skipped')
                print(sys.exc_info()[0],sys.exc_info()[1])
    return (fcount,dcount)

def getargs():
    '''
    获取并验证文件目录名参数，碰到错误是默认返回None
    '''
    try:
        dirForm,dirTo = sys.argv[1:]
    except:
        print("参数错误，使用cpall.py 源文件夹名 目标文件夹名")
    else:
        if not os.path.isdir(dirForm):
            print("错误：源文件夹不存在！")
        elif not os.path.exists(dirTo):
            os.mkdir(dirTo)
            print("注意：创建了目标文件夹.")
            return (dirForm,dirTo)
        else:
            print("警告：目标文件夹已存在")
            if hasattr(os.path,'samefile'):
                same = os.path.samefile(dirForm,dirTo)
            else:
                same = os.path.abspath(dirForm) == os.path.abspath(dirTo)
            if same:
                print("出错：目标文件和源文件一致")
            else:
                return (dirForm,dirTo)

if __name__ =="__main__":
    import time
    dirstuple = getargs()
    if dirstuple:
        print("开始复制........")
        start = time.clock()
        fcount,dcount = copyTree(*dirstuple)
        print("copied",fcount,'files',dcount,'directories',end='')
        print('in',time.clock()-start,'seconds')