input: def compare_string_lengths(list1, list2):
      '''
      Write a python function that takes two lists of strings and returns the one 
      with the smaller total length of all strings combined.
  
      If both lists have the same total character count, return the first list.
  
      Examples
      compare_string_lengths([], []) ➞ []
      compare_string_lengths(['hello', 'world'], ['Hello', 'World']) ➞ ['Hello', 'World']
      compare_string_lengths(['foo', 'bar'], ['foo', 'bar', 'baz']) ➞ ['foo', 'bar']
      compare_string_lengths(['a', 'b'], ['A', 'B', 'C']) ➞ ['A', 'B', 'C']
      compare_string_lengths(['x'], ['y', 'z', 'w', 'v']) ➞ ['x']
      '''
output:     
      len1 = sum(len(s) for s in list1)
      len2 = sum(len(s) for s in list2)
      
      if len1 < len2:
          return list1
      elif len1 > len2:
          return list2
      else:
          return list1
  