异常处理

Try Except 形式

try:
    a = 1 / 0 # trigger the exception on purpose
except ZeroDivisionError:
    print("cannot divide by zero")

多个 Except

try:
    a = int("NaN") # trigger the ValueError on purpose
    a / 0 # trigger the ZeroDivisionError on purpose
except ZeroDivisionError:
    print("cannot divide by zero")
except ValueError:
    print("invalid value for integer parsing")

Try Else 形式

try:
    a = int("5")
    a / 10
except ZeroDivisionError:
    print("cannot divide by zero")
except ValueError:
    print("invalid value for integer parsing")
else:
    print("everything is ok")

代码挑战

修改编辑器中代码，触发指定的异常。