Python except 关键字
实例
如果语句引发错误,则打印 "Something went wrong":
- try:
- x > 3
- except:
- print("Something went wrong")
定义和用法
在 try … except 块中使用了关键字 except。它定义 try 块引发错误时要运行的代码块。
您可以为不同的错误类型定义不同的块,以及没有问题的情况下执行的块,请参见下面的例子。
更多实例
实例 1
如果引发 NameError 则写一条消息,如果引发 TypeError 则写另一条:
- x = "hello"
- try:
- x > 3
- except NameError:
- print("You have a variable that is not defined.")
- except TypeError:
- print("You are comparing values of different type")
实例 2
尝试执行一条引发错误的语句,但没有定义的错误类型(在这种情况下为 ZeroDivisionError):
- try:
- x = 1/0
- except NameError:
- print("You have a variable that is not defined.")
- except TypeError:
- print("You are comparing values of different type")
- except:
- print("Something else went wrong")
实例 3
如果没有出现错误,写一条消息:
- x = 1
- try:
- x > 10
- except NameError:
- print("You have a variable that is not defined.")
- except TypeError:
- print("You are comparing values of different type")
- else:
- print("The 'Try' code was executed without raising any errors!")