Python except 关键字

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。

实例一

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")

# 结果： You are comparing values of different type

实例二

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")

# 结果： Something else went wrong

实例三

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!")

# 结果：The 'Try' code was executed without raising any errors!