Python执行系统命令的方法

Python中执行系统命令常见方法有两种：

两者均需 import os

(1) os.system

# 仅仅在一个子终端运行系统命令，而不能获取命令执行后的返回信息

system(command) -> exit_status
Execute the command (a string) in a subshell.

# 如果再命令行下执行，结果直接打印出来

1

>>>
 os.system('ls')

2

04101419778.CHMbash
 document media py-django
 video

3

11.wmvbooks
 downloads Pictures python

4

all-20061022Desktop
 Examples project tools

(2) os.popen

#该方法不但执行命令还返回执行后的信息对象

popen(command [, mode='r' [, bufsize]]) -> pipe
Open a pipe to/from a command returning a file object.

例如：

01

>>>tmp=os.popen('ls
 *.py').readlines()

02

>>>tmp

03

Out[21]:

04

['dump_db_pickle.py
 ',

05

'dump_db_pickle_recs.py
 ',

06

'dump_db_shelve.py
 ',

07

'initdata.py
 ',

08

'__init__.py
 ',

09

'make_db_pickle.py
 ',

10

'make_db_pickle_recs.py
 ',

11

'make_db_shelve.py
 ',

12

'peopleinteract_query.py
 ',

13

'reader.py
 ',

14

'testargv.py
 ',

15

'teststreams.py
 ',

16

'update_db_pickle.py
 ',

17

'writer.py
 ']

好处在于：将返回的结果赋于一变量，便于程序的处理。

(3) 使用模块subprocess

1

>>>importsubprocess

2

>>>
 subprocess.call (["cmd","arg1","arg2"],shell=True)

获取返回和输出:

1

importsubprocess

2

p=subprocess.Popen('ls',
 shell=True,
 stdout=subprocess.PIPE,
 stderr=subprocess.STDOUT)

3

forlineinp.stdout.readlines():

4

printline,

5

retval=p.wait()

(4) 使用模块commands模块

1

>>>importcommands

2

>>>dir(commands)

3

['__all__','__builtins__','__doc__','__file__','__name__','getoutput','getstatus','getstatusoutput','mk2arg','mkarg']

4

>>>
 commands.getoutput("date")

5

'Wed
 Jun 10 19:39:57 CST 2009'

6

>>>

7

>>>
 commands.getstatusoutput("date")

8

(0,'Wed
 Jun 10 19:40:41 CST 2009')

注意：当执行命令的参数或者返回中包含了中文文字，那么建议使用subprocess，如果使用os.popen则会出现下面的错误:

查看源代码
打印帮助

1

Traceback
 (most recent call last):

2

File"./test1.py",
 line 56,in<module>

3

main()

4

File"./test1.py",
 line 45,inmain

5

fax.sendFax()

6

File"./mailfax/Fax.py",
 line 13,insendFax

7

os.popen(cmd)

8

UnicodeEncodeError:'ascii'codec
 can't encode charactersinposition
 46-52: ordinal notinrange(128)