docs: def edits1(word):
      "All edits that are one edit away from `word`."
      letters = 'qwertyuiopasdfghjklzxcvbnm'
      splits = [(word[:i], word[i:]) for i in range(len(word) + 1)]
      print('splits = ', splits)
      deletes = [L + R[1:] for L, R in splits if R]
      print('deletes = ', deletes)
      transposes = [L + R[1] + R[0] + R[2:] for L, R in splits if len(R) > 1]
      print('transposes = ', transposes)
      replaces = [L + c + R[1:] for L, R in splits if R for c in letters]
      print('replaces = ', replaces)
      inserts = [L + c + R for L, R in splits for c in letters]
      print('inserts = ', inserts)
      print(deletes + transposes + replaces + inserts)
      print(len(set(deletes + transposes + replaces + inserts)))
      return deletes + transposes + replaces + inserts