How to Modify Environment Variables for subprocess.Popen without Affecting the Current Process?

Using os.environ.copy() for Environment Modification in Python subprocess.Popen

In Python, manipulating the environment variables of an external process launched via subprocess.Popen is often necessary. One approach is to directly modify the os.environ dictionary, as demonstrated in the original code snippet:

import subprocess, os
my_env = os.environ
my_env["PATH"] = "/usr/sbin:/sbin:" + my_env["PATH"]
subprocess.Popen(my_command, env=my_env)

However, there exists a more optimal method that preserves the integrity of the original os.environ for the current process. The recommended approach is to create a copy of os.environ using the copy() method and modify the desired environment variables in the copy. This ensures that any changes made to the environment for the external process do not affect the current process:

import subprocess, os
my_env = os.environ.copy()
my_env["PATH"] = f"/usr/sbin:/sbin:{my_env['PATH']}"
subprocess.Popen(my_command, env=my_env)

This method provides a cleaner and more efficient way to modify the environment for external processes in Python. It prevents any unintentional alterations to the original os.environ while allowing you to customize the environment as needed for the subprocess.

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