从 Python 中将文件名传递给子进程

Question

I'm having problems calling an external command from within a python routine. I've written code before that calls simple commands but this one is a bit trickier and I'm just floundering around and getting nowhere.

The command is one of the GMT (Generic Mapping Tools) commands - "gmtselect" which takes a file of latitude/longitude coordinates and sees which ones are within a polygon defined by a series of lat/long points in a separate file.

If we call these two file "points.txt" and "polygon.txt" then from the command line the call would be:

gmtselect <polygon.txt -Fpolygon.txt 

I've tried various ways but cannot see how to do this using subprocess.Popen

Any informed suggestions?

Answer 1

import subprocess

with open('filename.txt') as f:
    subprocess.run(['gmtselect', '-Fother.txt'], stdin=f)