I would like to extract values corresponding to variable DIHED (here 4660.1650) and getting also the mean value from all DIHED.
To just pull the DIHED values, you can use this: import re find_dihed_re = re.compile(r'\bDIHED\s*=\s*([.-e\d]+)', re.I) total = count = 0 for line in file('file.txt'): m = find_dihed_re.search(line) if m: str_value = m.group(1) try: f = float(str_value) total += f count += 1 except: print "Not a float: %s" % str_value print "Total:", total print "Count:", count if count: print "Average:", total/count If you want a general parser for the file, it takes a bit more work. -tkc -- http://mail.python.org/mailman/listinfo/python-list