[SOLVED] Wildcard * not interpreted by python argparse on Windows

Wildcard * not interpreted by python argparse on Windows

I'm trying to write a script that could take all files in a directory and allowing the user to use the * to refer to multiple files.

This is the line in which I set up the parser to receive the input files:

parser.add_argument('-f', '--files', help='The files to compare.', required=True, nargs='+')

This is the line of the error

Invalid argument: '.\\rmsd\\*.xyz'

This is the code I run to execute the script

python .\rsmd.py -r .\rmsd\1.xyz -f .\rmsd\*.xyz

My purpose is to let the user use the script in Windows and in Linux.

Solution

On Windows, python only receives the .\rmsd\*.xyz as string, it doesn't evaluate which files match the pattern. you can use e.g. the glob module to parse that.

import glob
my_txt_files = glob.glob("*.txt")  # returns list of filenames in current directory matching the pattern
# e.g.:
matched_files = glob.glob(arguments.files)

Edit for platforms:

You could check if more than one file was matched to make it more platform-independent

import argparse
import glob

parser = argparse.ArgumentParser()
parser.add_argument('-f', '--files', nargs='+')
arguments = parser.parse_args()
matched_files = []
for file in arguments.files:
    if glob.escape(file) != file:
        # -> There are glob pattern chars in the string
        matched_files.extend(glob.glob(file))
    else:
        matched_files.append(file)

If you don't want to handle it in the program, you can start the program on Powershell with prior extension like this

python rsmd.py -f (get-childitem *.txt)