stemming.py

def replace_word(roots: list, sentence: str) -> str:
  output = []
  sentence_list = sentence.split()
  for word in sentence_list:
    output.append(word)
    for r in roots:
      if word.startswith(r):
        output[-1] = r

  return " ".join(output)

replace_word(roots=['cat', 'bat', 'rat'], sentence='the cattle was rattled by battery')