try:
    dic = {'a': 1,}
    dic['b']  # KeyError

    lst = ['a', 'b']
    lst[10]  # IndexError

    s = "2GB"
    s = int(s)  # ValueError

except ValueError as e:  # e为异常的值
    print(e)
except KeyError as e:
    print(e)
except IndexError as e:
    print(e)
except Exception as e:  # 万能异常
    print(e)
else:
    print("没有异常会执行我.")  # 一般用来关闭文件等操作
finally:
    print("有没有异常都会执行我")

# 异常包括三部分: 追踪信息/异常类型/异常的值
# try:
#     被检测的代码块
# except 异常类型：
#     try中一旦检测到异常，就执行这个位置的逻辑