从 Python 脚本运行 npm 脚本。 获得不一致的行为

Question

I have a directory containing some python scripts. In this directory there are subdirectories in the form of 'a/b/c1', 'a/b/c2', ..., 'a/b/cn', etc. Each of these directories is an npm package with a script in the package.json file called my_script .

From the directory with my python scripts I can run the following command from the terminal fine:

npm run my_script --prefix a/b/c1

However in my python script I doing something along the lines the following:

bashCmd = ['npm', 'run', 'my_script', '--prefix', 'a/b/c1']
process = subprocess.Popen(bashCmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
output, error = process.communicate()
print(output)
print(error)

The result of output is the message from npm telling you instructions on arguments to pass to it.

Usage: npm <command>

where <command> is one of:
    access, adduser, audit, bin, bugs, c, cache, ci, cit,...

From what I can tell, I am running the same set of instructions, one from Python, and one from npm, but getting different results.

Can anybody help me shed some light on this?

Answer 1

It seems I might have been looking at some older documentation or plain misinterpreted what I was reading for subprocess.Popen() . I was under the impression the input passed to this function was supposed to be a list of strings where each string would normally be separated by a space if you were to type the command directly into the terminal. If you just take the normal command and pass this as input like below, the program executes correctly.

bashCmd = ['npm run my_script --prefix a/b/c1']
process = subprocess.Popen(bashCmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
output, error = process.communicate()
print(output)
print(error)