python - Look for files not having a given extension -

i'v tried following code.

import re  regobj = re.compile(r"^.+\.(oth|xyz)$")  test in ["text.txt", "other.oth", "abc.xyz"]:     if regobj.match(test):         print("method 1:", test)  regobj = re.compile(r"^.+\.[^txt]$")  test in ["text.txt", "other.oth", "abc.xyz"]:     if regobj.match(test):         print("method 2:", test) 

i 2nd method finds file not having extension txt way try not one. doing wrong ?

regular expressions overkill here. use str.endswith() method:

if not str.endswith('.txt'): 

your regular expression uses negative character class, set of characters should not matched. not t or x satisfy test. have explicitly matched .txt , used not exclude rather include:

regobj = re.compile(r"^.+\.txt$")  if not regobj.match(test): 

if can use regular expressions, use negative look-ahead assertions;

 regobj = re.compile(r"^[^.]+\.(?!txt$)[^.]+$") 

here (?!...) matches locations there no literal txt following, way end of string. [^.]+ matches number of characters not . character until end of string.