Python Pexpect库的简单使用方法

#-*- coding:UTF-8 -*-
import pexpect
# 定义ssh连接
def ssh(user,host,password,command):
  #创建子应用，命令是 ssh -l root 127.0.0.1 python /home/python/test.py
  child = pexpect.spawn('ssh -l %s %s %s'%(user,host,command))
  # 期待开启的子程序的显示，子程序的不同显示会匹配到不同key然后我们定义不同的操作
  # 0 ： 连接超时
  # 1 ：ssh有时候提示你是否确认连接
  # 2 ：提示输入密码
  # 3 ：匹配到#号，表示命令已经执行完毕。没用到
  i = child.expect([pexpect.TIMEOUT, 'Are you sure you want to continue connecting','password:',r"([^-]>|#)"])
  # 如果登录超时，renturn none
  if i == 0: # Timeout
    print "Timeout"
    return None
  # 提示是否确认连接
  if i == 1: 
    child.sendline ('yes') # 我们输入yes
    child.expect ('password: ')# 输入yes后 子程序应该提示输入密码，我们再次期待password
    i = child.expect([pexpect.TIMEOUT, 'password: '])
    #超时
    if i == 0: # Timeout
        return None
  # 不考虑其他情况，走到此处时，要么timeout 已经return ，要么等待输入密码
  #输入密码
  child.sendline(password)
  # 返回子程序
  return child
if __name__ =='__main__':
  try:
    # 配置数据
    host='127.0.0.1'
    user="root"
    password = '********'
    command = 'python /home/python/test.py'
    #command="ls -l"
    child = ssh(user,host,password,command)
    #这句是将子程序的命令行拉到末端
    test = child.expect(pexpect.EOF)
    #child中before就是我们要的数据，有时候还会在 after中
    print child.before
    print child.after
  except Exception,e:
    print str(e)
# 最终的显示结果是 test.py中打印的hahaha结果，
[root@localhost python]# python test_pexpect.py 
 
hahaha


<class 'pexpect.exceptions.EOF'>

# ip 192.168.233.133
# user root
# 在另一台虚拟机的相同位置创建/home/pyhton/test.py 内容如下
if __name__=="__main__":
  print "another virual machine hahaha"
# 打印结果
[root@localhost python]# python test3.py
 
another virual machine hahaha

<class 'pexpect.exceptions.EOF'>

# --*-- coding:utf-8 --*--
import pexpect
import os
import time
def sftp(ip , password , command):
        # 创建子应用
        child = pexpect.spawn("sftp %s"%(ip))
        i = child.expect([pexpect.TIMEOUT,'password:'])
        # 超时
        if i == 0 :
            print "Timeout"
            return None
        # 准备输入密码
        if i == 1 :
            # 输入密码
            child.sendline(password)
            j = child.expect([pexpect.TIMEOUT,'sftp>'])
            # 超时
            if j == 0:
                print "Timeout"
                return None
            # 匹配到进入sftp命令模式
            if j==1:
                print 'Before sftp get command'
                print child.before
                print "-----------------"
                #发送命令
                child.sendline(command)
                child.expect(['sftp>'])
                print "After sftp get command"
                print child.before
                print "-----------------"
                child.sendline("bye")
                #child.expect(['sftp>'])
                print "After sftp bye"
                print child.before
                print "-----------------"
                print child.after
                return child
if __name__=='__main__':
        ip = "192.168.233.133"
        command = "get /home/python/test.txt"
        password = "********"
        child = sftp(ip , password , command)
        print child.before
        print child.after
        if os.path.exists("./test.txt"):
                print "Make sure transfer successfully"
        else :
                print "Can not find the transfer file"

# ----------------------------结果-----------------------------------------------
'''
Before sftp get command
 
Connected to 192.168.233.133.

-----------------
After sftp get command
 get /home/python/test.txt
Fetching /home/python/test.txt to test.txt
/home/python/test.txt             100%  73  25.2KB/s  00:00  

-----------------
After sftp bye
 get /home/python/test.txt
Fetching /home/python/test.txt to test.txt
/home/python/test.txt             100%  73  25.2KB/s  00:00  

-----------------
sftp>
 get /home/python/test.txt
Fetching /home/python/test.txt to test.txt
/home/python/test.txt             100%  73  25.2KB/s  00:00  

sftp>
Make sure transfer successfully
'''