python实现从ftp上下载文件的实例方法

python从ftp上下载文件的方法：

首先导入ftp模块；

然后使用【chdir】命令切换工作路径；

再使用“self.ftp.nlst()”命令获取目录下的文件；

最后使用“self.ftp.retrbinary()”命令下载ftp文件即可。

#!/usr/bin/python
# coding=utf-8
import os
from ftplib import FTP # 引入ftp模块
class MyFtp:
 ftp = FTP()  
 def __init__(self,host,port=21):
   self.ftp.connect(host,port)  
 def login(self,username,pwd):
   self.ftp.set_debuglevel(2) # 打开调试级别2，显示详细信息    
   self.ftp.login(username,pwd)    
   p
rint(self.ftp.welcome)  
 def downloadFile(self,localpath,remotepath,filename):
   os.chdir(localpath)  # 切换工作路径到下载目录
   self.ftp.cwd( remotepath)  # 要登录的ftp目录
   self.ftp.nlst() # 获取目录下的文件
   file_handle = open(filename,"wb").write  # 以写模式在本地打开文件
   self.ftp.retrbinary('RETR ％s' ％ os.path.basename(filename),file_handle,blocksize=1024) # 下载ftp文件
   # ftp.delete（filename） # 删除ftp服务器上的文件
 def close(self):
   self.ftp.set_debuglevel(0) # 关闭调试    
   self.ftp.quit()if __name__ == '__main__':
 ftp = MyFtp('host')
 ftp.login('username','pwd')
 ftp.downloadFile('E:\\RED\\workspace\\appAuto\\apk\\Android10','/mobile/Android/release10/','xxx.apk')
 ftp.close()

实例扩展：

#coding=utf-8
'''
ftp自动下载、自动上传脚本，可以递归目录操作
'''

from ftplib import FTP
import os,sys,string,datetime,time
import socket

class MYFTP:
def __init__(self, hostaddr, username, password, remotedir, port=21):
self.hostaddr = hostaddr
self.username = username
self.password = password
self.remotedir = remotedir
self.port = port
self.ftp = FTP()
self.file_list = []
# self.ftp.set_debuglevel(2)
def __del__(self):
self.ftp.close()
# self.ftp.set_debuglevel(0)
def login(self):
ftp = self.ftp
try:
timeout = 300
socket.setdefaulttimeout(timeout)
ftp.set_pasv(True)
print u'开始连接到 ％s' ％(self.hostaddr)
ftp.connect(self.hostaddr, self.port)
print u'成功连接到 ％s' ％(self.hostaddr)
print u'开始登录到 ％s' ％(self.hostaddr)
ftp.login(self.username, self.password)
print u'成功登录到 ％s' ％(self.hostaddr)
debug_print(ftp.getwelcome())
except Exception:
print u'连接或登录失败'
try:
ftp.cwd(self.remotedir)
except(Exception):
print u'切换目录失败'

def is_same_size(self, localfile, remotefile):
try:
remotefile_size = self.ftp.size(remotefile)
except:
remotefile_size = -1
try:
localfile_size = os.path.getsize(localfile)
except:
localfile_size = -1
debug_print('localfile_size:％d remotefile_size:％d' ％(localfile_size, remotefile_size),)
if remotefile_size == localfile_size:
return 1
else:
return 0
def download_file(self, localfile, remotefile):
if self.is_same_size(localfile, remotefile):
debug_print(u'％s 文件大小相同，无需下载' ％localfile)
return
else:
debug_print(u'>>>>>>>>>>>>下载文件 ％s ... ...' ％localfile)
#return
file_handler = open(localfile, 'wb')
self.ftp.retrbinary(u'RETR ％s'％(remotefile), file_handler.write)
file_handler.close()

def download_files(self, localdir='./', remotedir='./'):
try:
self.ftp.cwd(remotedir)
except:
debug_print(u'目录％s不存在，继续...' ％remotedir)
return
if not os.path.isdir(localdir):
os.makedirs(localdir)
debug_print(u'切换至目录 ％s' ％self.ftp.pwd())
self.file_list = []
self.ftp.dir(self.get_file_list)
remotenames = self.file_list
#print(remotenames)
#return
for item in remotenames:
filetype = item[0]
filename = item[1]
local = os.path.join(localdir, filename)
if filetype == 'd':
self.download_files(local, filename)
elif filetype == '-':
self.download_file(local, filename)
self.ftp.cwd('..')
debug_print(u'返回上层目录 ％s' ％self.ftp.pwd())
def upload_file(self, localfile, remotefile):
if not os.path.isfile(localfile):
return
if self.is_same_size(localfile, remotefile):
debug_print(u'跳过[相等]: ％s' ％localfile)
return
file_handler = open(localfile, 'rb')
self.ftp.storbinary('STOR ％s' ％remotefile, file_handler)
file_handler.close()
debug_print(u'已传送: ％s' ％localfile)
def upload_files(self, localdir='./', remotedir = './'):
if not os.path.isdir(localdir):
return
localnames = os.listdir(localdir)
self.ftp.cwd(remotedir)
for item in localnames:
src = os.path.join(localdir, item)
if os.path.isdir(src):
try:
self.ftp.mkd(item)
except:
debug_print(u'目录已存在 ％s' ％item)
self.upload_files(src, item)
else:
self.upload_file(src, item)
self.ftp.cwd('..')

def get_file_list(self, line):
ret_arr = []
file_arr = self.get_filename(line)
if file_arr[1] not in ['.', '..']:
self.file_list.append(file_arr)

def get_filename(self, line):
pos = line.rfind(':')
while(line[pos] != ' '):
pos += 1
while(line[pos] == ' '):
pos += 1
file_arr = [line[0], line[pos:]]
return file_arr
def debug_print(s):
print s

if __name__ == '__main__':
timenow = time.localtime()
datenow = time.strftime('％Y-％m-％d', timenow)
# 配置如下变量
hostaddr = '211.15.113.45' # ftp地址
username = 'UserName' # 用户名
password = '123456' # 密码
port = 21 # 端口号
rootdir_local = 'E:/mypiv' # 本地目录
rootdir_remote = '/PIV'  # 远程目录

f = MYFTP(hostaddr, username, password, rootdir_remote, port)
f.login()
f.download_files(rootdir_local, rootdir_remote)

timenow = time.localtime()
datenow = time.strftime('％Y-％m-％d', timenow)
logstr = u"％s 成功执行了备份n" ％datenow
debug_print(logstr)

来源：https://www.py.cn/jishu/gaoji/19626.html