関連ワード:  check a word in a string python    search a word in a string python    check if word in a string python    check if a word appears in a string python    check specific word in string python    how to check each word in a string python    how to check if a word is repeated in a string python    how to check if a word is not in a string python    how to check how many times a word appears in a string python    check if a string contains a specific word in python