子进程：FileNotFound

Question

谁能给我解释一下这个错误：

>>> def j():
...     import subprocess
...     print(subprocess.Popen(['command', '-v', 'nmcli'],     stdout=subprocess.PIPE, stderr=subprocess.PIPE))
... 
>>> j()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 3, in j
File "/usr/lib/python3.4/subprocess.py", line 859, in __init__
restore_signals, start_new_session)
File "/usr/lib/python3.4/subprocess.py", line 1457, in _execute_child
raise child_exception_type(errno_num, err_msg)
FileNotFoundError: [Errno 2] No such file or directory: 'command'

我尝试将字符串作为列表，它不会改变任何东西。

Answer 1

FileNotFoundError: [Errno 2] 没有这样的文件或目录：'command'

command 是一个内置的 shell。 subprocess.Popen 默认不运行 shell。

要运行 shell，请传递 shell=True:

>>> import subprocess
>>> subprocess.check_output('command -v python', shell=True)
b'/usr/bin/python\n'

要查找可执行文件的完整路径，您可以use shutil.which() instead:

>>> import shutil
>>> shutil.which('python')
'/usr/bin/python'