input: def compare_total_chars(list1, list2):
      '''
      Write a python function that compares two lists of strings and returns the one in which
      the total number of characters in all the strings is smaller than the other list.
  
      In case both lists have the same number of characters, return the first list.
  
      Examples
      compare_total_chars([], []) ➞ []
      compare_total_chars(['hi', 'admin'], ['hI', 'Hi']) ➞ ['hI', 'Hi']
      compare_total_chars(['hi', 'admin'], ['hi', 'hi', 'admin', 'project']) ➞ ['hi', 'admin']
      compare_total_chars(['hi', 'admin'], ['hI', 'hi', 'hi']) ➞ ['hI', 'hi', 'hi']
      compare_total_chars(['4'], ['1', '2', '3', '4', '5']) ➞ ['4']
      '''
output:     total_chars_list1 = sum(len(s) for s in list1)
      total_chars_list2 = sum(len(s) for s in list2)
      
      if total_chars_list1 <= total_chars_list2:
          return list1
      else:
          return list2