可以執行shell命令的相關模塊和函數有:
以上執行shell命令的相關的模塊和函數的功能均在 subprocess 模塊中實現,并提供了更豐富的功能。
subprocess
call
執行命令,返回狀態碼
>>> 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)0check_call
執行命令,如果執行狀態碼是 0 ,則返回0,否則拋異常
>>> 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 1check_output
執行命令,如果狀態碼是 0 ,則返回執行結果,否則拋異常
>>> 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 1subprocess.Popen(...)
用于執行復雜的系統命令
參數:
args:shell命令,可以是字符串或者序列類型(如:list,元組)
bufsize:指定緩沖。0 無緩沖,1 行緩沖,其他 緩沖區大小,負值 系統緩沖
stdin, stdout, stderr:分別表示程序的標準輸入、輸出、錯誤句柄
preexec_fn:只在Unix平臺下有效,用于指定一個可執行對象(callable object),它將在子進程運行之前被調用
close_sfs:在windows平臺下,如果close_fds被設置為True,則新創建的子進程將不會繼承父進程的輸入、輸出、錯誤管道。
所以不能將close_fds設置為True同時重定向子進程的標準輸入、輸出與錯誤(stdin, stdout, stderr)。
shell:同上
cwd:用于設置子進程的當前目錄
env:用于指定子進程的環境變量。如果env = None,子進程的環境變量將從父進程中繼承。
universal_newlines:不同系統的換行符不同,True -> 同意使用 n
startupinfo與createionflags只在windows下有效
將被傳遞給底層的CreateProcess()函數,用于設置子進程的一些屬性,如:主窗口的外觀,進程的優先級等等
執行普通命令
>>> 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>終端輸入的命令分為兩種:
>>> 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', '')新聞熱點
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