these are built-in, I tried both:
from glob import glob
mydir = "C:/tmp/"
file_list = glob(mydir + "*.opju")
print('file_list {}'.format(file_list))
and
import os
from fnmatch import fnmatch
mydir = "C:/tmp"
file_list = [file for file in os.listdir(mydir) if fnmatch(file, '*.opju')]
print('file_list {}'.format(file_list))
No need to install.
CP