input: Write a function to delete characters from a string that match a given pattern.
  assert delete_pattern_characters("hello world", "l") == "heo word"
  assert delete_pattern_characters("foobar", "o") == "fbar"
  assert delete_pattern_characters("123-456-7890", "\d") == "--"
output: def delete_pattern_characters(s, pattern):
      import re
      return re.sub(pattern, '', s)