How can I execute a program or call a system command in Python run command?
How can I call an external command within Python, similar to how I would type it in a shell or command prompt?
As someone who’s dabbled with this a lot, one reliable way is by using the subprocess.run() function. It lets you execute a command as if you typed it directly into the shell, with additional control over input, output, and error handling. You even get a CompletedProcess object that provides details like return codes and output.
Example:
import subprocess
result = subprocess.run(['ls', '-l'], capture_output=True, text=True)
print(result.stdout)
This runs the ls -l command (common in Unix-like systems) and captures its output, making it versatile for more complex tasks.
Building on that, if you’re looking for something simpler and less code-heavy, you might consider os.system(). While it’s not as feature-rich as subprocess.run(), it’s a classic option for quick commands. Just keep in mind, it doesn’t directly capture the command’s output or errors.
Example:
import os
os.system('ls -l')
This will run the same ls -l command, but the output goes straight to the console. It’s great for straightforward tasks, but for more control, subprocess.run() is the better option.
Good points so far! For something in between os.system() and subprocess.run(), there’s also subprocess.call(). It executes commands, waits for them to finish, and returns their exit code. However, like os.system(), it doesn’t capture output unless you explicitly handle it.
Example:
import subprocess
return_code = subprocess.call(['ls', '-l'])
print(f'Command returned {return_code}')
This approach runs the ls -l command and tells you if it succeeded (return code 0) or failed. While it’s less flexible than subprocess.run(), it can be a simpler option in certain cases.
So, between python run command approaches, you’ve got tools ranging from quick-and-simple to full control over outputs and errors!