Here is a typical example for using readlines().
#!/usr/bin/env python import traceback import sys fname = "/online_dir/" + "dbHostsTangoExplorer.lis" try: inp = open( fname, 'r') except Exception as e: print( " ", sys.exc_info()[0]) print( " ", e) exc_type, exc_value, exc_traceback = sys.exc_info() traceback.print_tb(exc_traceback, limit=None, file=sys.stdout) sys.exit( 255) dbHosts = [] for line in inp.readlines(): if line.strip().find( '#') == 0: continue dbHosts.append( line.strip()) inp.close()