在不同的文件夹中执行命令行

我正在使用 os.system(command)调用 Python 中的命令行程序。

我如何调用这个命令传递一个不同的文件夹执行？有这样的系统调用吗？或者我应该保存当前文件夹，并在执行后更改恢复它。

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小开

Try to os.chdir(path) before invoking the command.

From here:

os.chdir(path) Change the current working directory to path.

Availability: Unix, Windows

EDIT

This will change the current working dir, you can get the current working by:

os.getcwd()

If you want to save it and restore it later, if you need to do some work in the original working dir.

EDIT 2

In any case you should probably move to subprocess (doc) as suggested here. If you use subprocess's Popen you have the choice of providing cwd parameter to specify the working directory for the subprocess: read this.

subprocess.Popen(args, bufsize=0, executable=None, stdin=None,
stdout=None, stderr=None, preexec_fn=None, close_fds=False,
shell=False, cwd=None, env=None, universal_newlines=False,
startupinfo=None, creationflags=0)

...

If cwd is not None, the child’s current directory will be changed to cwd before it is executed. Note that this directory is not considered when searching the executable, so you can’t specify the program’s path relative to cwd.

小开
最佳答案

The subprocess module is a very good solution.

import subprocess
p = subprocess.Popen([command, argument1,...], cwd=working_directory)
p.wait()

It has also arguments for modifying environment variables, redirecting input/output to the calling program, etc.

小开

Here, I made a little function to change the path you're working on :

import os
def make_path(r_path):
ack = 1
try:
root = os.path.dirname(__file__)
rel_path = os.path.join("..", r_path)


abs_path = os.path.join(root, rel_path)
os.chdir(abs_path)
ack = 0
except Exception as details:
print('problem to get to the path '+r_path+' (0001) : ' + str(details))
return ack

So here, r_path is the relative path you want to go to. I added ".." to the path.join() methode so, if you're in a folder and want to exit it before searching for your path, it does it automatically. So, if your relative directory looks like this :

-path_to_reach
-a_random_file.txt
-your_current_folder
-your_program.py

you can do those lines to go inside the path_to_reach and make your command, in exemple :

command = ls
make_path('path_to_reach/')
os.system(command)

This command would not be useful, but you see the idea!


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