从最后一组字符中选择最后一组字符之间的子串

def extract_substring_from_last_group_of_characters(string):
    start_marker = "{"  # 开始标记
    end_marker = "}"  # 结束标记

    # 查找最后一组字符的起始位置和结束位置
    start_index = string.rfind(start_marker) + len(start_marker)
    end_index = string.rfind(end_marker)

    # 提取最后一组字符之间的子串
    substring = string[start_index:end_index]

    return substring

# 测试示例
string = "abc{def}ghi{jkl}"
substring = extract_substring_from_last_group_of_characters(string)
print(substring)  # 输出 "jkl"