関連ワード:  if a character in a string python    check if a character in a string python    if a letter is in a string python    check if a letter in a string python    check if a character exists in a string python    find if a character is in a string python    see if a character is in a string python    check if a character is present in a string python    check if a character is not in a string python    check if a letter exists in a string python