可以执行shell命令的相关模块和函数有:
以上执行shell命令的相关的模块和函数的功能均在 subprocess 模块中实现,并提供了更丰富的功能。
subprocess
call
执行命令,返回状态码
>>> import subprocess>>> ret = subprocess.call(["ls", "-l"], shell=False)total 4684-rw-r--r-- 1 root root 454 May 5 12:20 aa.py-rw-r--r-- 1 root root 0 May 8 16:51 aa.txt-rw-r--r-- 1 root root 4783286 Apr 11 16:39 DockerToolbox.exe-rw-r--r-- 1 root root 422 May 5 12:20 ip_info.txt-rw-r--r-- 1 root root 718 Apr 19 10:52 my.cnf>>> ret = subprocess.call("ls -l", shell=True)total 4684-rw-r--r-- 1 root root 454 May 5 12:20 aa.py-rw-r--r-- 1 root root 0 May 8 16:51 aa.txt-rw-r--r-- 1 root root 4783286 Apr 11 16:39 DockerToolbox.exe-rw-r--r-- 1 root root 422 May 5 12:20 ip_info.txt-rw-r--r-- 1 root root 718 Apr 19 10:52 my.cnf>>> print(ret)0
check_call
执行命令,如果执行状态码是 0 ,则返回0,否则抛异常
>>> subprocess.check_call(["ls", "-l"])total 4684-rw-r--r-- 1 root root 454 May 5 12:20 aa.py-rw-r--r-- 1 root root 0 May 8 16:51 aa.txt-rw-r--r-- 1 root root 4783286 Apr 11 16:39 DockerToolbox.exe-rw-r--r-- 1 root root 422 May 5 12:20 ip_info.txt-rw-r--r-- 1 root root 718 Apr 19 10:52 my.cnf0>>> subprocess.check_call("exit 1", shell=True)Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/local/python3.5/lib/python3.5/subprocess.py", line 581, in check_call raise CalledProcessError(retcode, cmd)subprocess.CalledProcessError: Command 'exit 1' returned non-zero exit status 1
check_output
执行命令,如果状态码是 0 ,则返回执行结果,否则抛异常
>>> subprocess.check_output(["echo", "Hello World!"])b'Hello World!/n'>>> subprocess.check_output("exit 1", shell=True)Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/local/python3.5/lib/python3.5/subprocess.py", line 626, in check_output **kwargs).stdout File "/usr/local/python3.5/lib/python3.5/subprocess.py", line 708, in run output=stdout, stderr=stderr)subprocess.CalledProcessError: Command 'exit 1' returned non-zero exit status 1
subprocess.Popen(...)
用于执行复杂的系统命令
参数:
args:shell命令,可以是字符串或者序列类型(如:list,元组)
bufsize:指定缓冲。0 无缓冲,1 行缓冲,其他 缓冲区大小,负值 系统缓冲
stdin, stdout, stderr:分别表示程序的标准输入、输出、错误句柄
preexec_fn:只在Unix平台下有效,用于指定一个可执行对象(callable object),它将在子进程运行之前被调用
close_sfs:在windows平台下,如果close_fds被设置为True,则新创建的子进程将不会继承父进程的输入、输出、错误管道。
所以不能将close_fds设置为True同时重定向子进程的标准输入、输出与错误(stdin, stdout, stderr)。
shell:同上
cwd:用于设置子进程的当前目录
env:用于指定子进程的环境变量。如果env = None,子进程的环境变量将从父进程中继承。
universal_newlines:不同系统的换行符不同,True -> 同意使用 n
startupinfo与createionflags只在windows下有效
将被传递给底层的CreateProcess()函数,用于设置子进程的一些属性,如:主窗口的外观,进程的优先级等等
执行普通命令
>>> import subprocess>>> ret1 = subprocess.Popen(["mkdir","t1"])>>> ret2 = subprocess.Popen("mkdir t2", shell=True)>>> print(ret1)<subprocess.Popen object at 0x7f4d7609dd30>>>> print(ret2)<subprocess.Popen object at 0x7f4d7609dc18>
终端输入的命令分为两种:
>>> import subprocess>>> obj = subprocess.Popen("mkdir t3", shell=True, cwd='/tmp/',)>>> import subprocess>>> obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)>>> obj.stdin.write("print(1)/n")9>>> obj.stdin.write("print(2)")8>>> obj.stdin.close()>>> cmd_out = obj.stdout.read()>>> obj.stdout.close()>>> cmd_error = obj.stderr.read()>>> obj.stderr.close()>>> print(cmd_out)12>>> print(cmd_error)
>>> import subprocess>>> >>> obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)>>> obj.stdin.write("print(1)/n")9>>> obj.stdin.write("print(2)")8>>> >>> out_error_list = obj.communicate()>>> print(out_error_list)('1/n2/n', '')
>>> obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)>>> out_error_list = obj.communicate('print("hello")')>>> print(out_error_list)('hello/n', '')
新闻热点
疑难解答