python 读取csv中的文件，从sftp下载文件

需要从sftp上下载一些图片文件，文件名存放在一个csv文件中。代码如下：

# -*- coding:utf-8 -*-
import paramiko
import csv
import os

def sft_download_all(host,port,username,password):
    sf = paramiko.Transport((host,port))
    sf.connect(username = username,password = password)
    sftp = paramiko.SFTPClient.from_transport(sf)

    csv_reader1=csv.reader(open(r'D:数据处理photo.csv',encoding='utf-8'))
    for row in csv_reader1:
        remote=row[2]
        filename=row[1]
        localfile='D:\训练数据\all\'+filename
        try:
            if sftp.stat(remote) and (not os.path.exists(localfile)):
                print("download:"+remote)
                sftp.get(remote,localfile)
        except Exception as e:
            print('出错跳过：file='+remote+' exception:',e)
            continue
    print("全部数据下载完毕！")

def sftp_download(host,port,username,password):
    sf = paramiko.Transport((host,port))
    sf.connect(username = username,password = password)
    sftp = paramiko.SFTPClient.from_transport(sf)

    csv_reader1=csv.reader(open(r'D:数据处理系安全带的.csv',encoding='utf-8'))
    for row in csv_reader1:
        remote=row[4]
        filename= os.path.basename(remote)
        localfile='D:\训练数据\hasbelt\'+filename
        try:
            if sftp.stat(remote) and (not os.path.exists(localfile)):
                print("download:"+remote)
                sftp.get(remote,localfile)
        except Exception as e:
            print('出错跳过：file='+remote+' exception:',e)
            continue
    print("通过数据下载完毕！")

    csv_reader2=csv.reader(open(r'D:数据处理没系安全带.csv',encoding='utf-8'))
    for row in csv_reader2:
        remote=row[4]
        filename= os.path.basename(remote)
        localfile='D:\训练数据\beltno\'+filename
        try:
            if sftp.stat(remote) and (not os.path.exists(localfile)):
                print("download:"+remote)
                sftp.get(remote,localfile)
        except Exception as e:
            print('出错跳过：file='+remote+' exception:',e)
            continue
    print("不通过数据下载完毕！")
    sf.close()

if __name__ == '__main__':
    host = '172.16.207.21'#主机
    port = 22 #端口
    username = 'root' #用户名
    password = 'data' #密码
    sftp_download(host,port,username,password)#下载
    #sft_download_all(host,port,username,password)