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.CHM bash document media py-django video 3 11.wmv books downloads Pictures python 4 all-20061022 Desktop 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:
1 >>>tmp = os.popen('ls *.py').readlines() 2 >>>tmp 3 Out[21]: 4 ['dump_db_pickle.py ', 5 'dump_db_pickle_recs.py ', 6 'dump_db_shelve.py ', 7 'initdata.py ', 8 '__init__.py ', 9 '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 >>> import subprocess 2 >>> subprocess.call (["cmd", "arg1", "arg2"],shell=True)
获取返回和输出:
1 import subprocess 2 p = subprocess.Popen('ls', shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT) 3 for line in p.stdout.readlines(): 4 print line, 5 retval = p.wait()
(4) 使用模块commands模块
1 >>> import commands 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:
1 Traceback (most recent call last): 2 File "./test1.py", line 56, in <module> 3 main() 4 File "./test1.py", line 45, in main 5 fax.sendFax() 6 File "./mailfax/Fax.py", line 13, in sendFax 7 os.popen(cmd) 8 UnicodeEncodeError: 'ascii' codec can't encode characters in position 46-52: ordinal not inrange(128)
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