input: Write a function to develop a regular expression in Python to match all numeric strings. If the input string matches the pattern, return True; otherwise, return False. If the input string is empty, return False.
  assert match_numerics("123456789")==True
  assert match_numerics("abc123")==False
  assert match_numerics("123.456")==False
  assert match_numerics("")==False
output: def match_numerics(s):
      if not s:
          return False
      return bool(re.fullmatch(r'\d+', s))