Python 脚本未安装 npm 包

Question

I have this code here in python

import subprocess

subprocess.Popen(["npm", "install", "express"], shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)

however it doesn't seem to work, it doesn't install anything. When I look at the error it tells me the proper usage of the npm command.

Keep in mind this is on Python 3.8.8 on Ubuntu 18.04

Answer 1

Instead of using subprocess , Try using os like this:

import os
os.system("npm install express")
os.system("echo You can run commands from terminal using os.")

Answer 2

import subprocess

proc = subprocess.Popen(["npm", "install", "express"])

I tested this on Ubuntu 20.04 and it ran the command as expected.

Only thing is that it gets stuck in the NPM process and I've had to press cancel to exit the process.

Answer 3

On my first post destroyer22719 commented:

Hi there! This worked for me, however may I ask how this one works while the other one doesn't? I believe it's important for me that subprocess works.

I would like to say, I never learned how to use subprocess, so I wouldn't know how it works or anything. But, with a little bit of looking around I think I found a solution.

I tested on the latest version of ubuntu as of a week ago (python 3.8.10) and on my windows 10 (python 3.9) and it fails on windows 10 but works on ubuntu.

Ubuntu Version:

import subprocess
from threading import Thread
def package():
    subprocess.Popen(["npm install express"], shell=True)
Thread(target=package).start()
print("This text will print if the command is finished or not.")

This is the one that works on windows:

import subprocess
from threading import Thread
def package():
    subprocess.Popen(["npm", "install", "express"], shell=True)
Thread(target=package).start()
print("This text will print if the command is finished or not.")

threading is imported because when you run the process it doesn't just stop, so I used Thread() to get around that.