使用Python的“子进程”运行“导出”命令不起作用 [英] Running 'export' command with Pythons 'subprocess' does not work

问题描述

subprocess.run('export FOO=BAR', shell=True)

这根本行不通，我也不知道为什么。

This simply doesn't work, and I have no idea why.

我要做的所有工作都是通过python设置环境变量（ 3.5.1）脚本，当我运行上述代码时，什么也没发生。没有错误，并且当我自己检查环境变量时，还没有设置它。

All I am trying to do I set an environment variable from my python (3.5.1) script, and when I run the above line, nothing happens. No errors are raised, and when I check the environment variable myself, it has not been set.

带有 subprocess.run（）的其他shell命令 做工作，例如 ls 和 pwd ，但是不是 export 。

Other shell commands with subprocess.run() do work, such as ls and pwd, but not export.

.run（）已添加在Python 3.5中（以防您不认识它），但是我还尝试了使用 .call（）和 .Popen（ ），结果不变。

.run() was added in Python 3.5 (in case you didn't recognise it), but I have also tried the above line with .call() and .Popen(), with no change in results.

我知道我可以使用 os.environ ['FOO'] = BAR ，但是我将在项目中大量使用shell命令，并且我希望我需要将多个命令串在一起，这将使 export 的使用比 os.environ 。

I am aware that I can set environment variables in python with os.environ['FOO'] = "BAR", but I will be using shell commands a lot in my project, and I expect that I will need to string multiple commands together, which will make using export easier than os.environ.

我的项目将在Linux上运行，而这正是我的机器在运行。

My project will run on Linux, which is what my machine is running on.

推荐答案

工作正常；但是，变量设置仅存在于子过程中。您不能从孩子那里影响本地过程的环境。

It works fine; however, the variable setting only exists in the subprocess. You cannot affect the environment of the local process from a child.

os.environ 是正确的解决方案，因为它将更改本地进程的环境，并且这些更改将由以 subprocess.run 开始的任何进程继承。

os.environ is the correct solution, as it changes the environment of the local process, and those changes will be inherited by any process started with subprocess.run.

您也可以将 env 参数用于 run ：

subprocess.run(["cmdname", "arg1", "arg number 2"], env=dict(FOO='BAR', **os.environ))

这将在包含 FOO = BAR 而不修改当前环境。

This runs the command in a modified environment that includes FOO=BAR without modifying the current environment.

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