I'm using below code to read multiple multiple CSV's in multiple Zipfiles (one CSV per Zipfile) and data is huge (each csv is 1.5GB and I have more than 30 zipped CSV's) and that's why I prefer not unzipping them. however, it gets very slow when I want to concat many of them. is there a more effecient code to make the process quicker?

     import os
     import glob
     import pandas as pd
     os.chdir(r"path") 
     extension = 'zip'
     all_filenames = [i for i in glob.glob('*.{}'.format(extension))]
     combined_csv = pd.concat([pd.read_csv(f) for f in all_filenames ])