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Python3 捕捉异常

时间:2016-05-30 14:10:09      阅读:215      评论:0      收藏:0      [点我收藏+]

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可以通过try/except语句来实现捕获异常,如下:

bpython version 0.15 on top of Python 3.5.1+ /usr/bin/python3
>>> x=3
>>> y=0
>>> x/y
Traceback (most recent call last):
  File "<input>", line 1, in <module>
    x/y
ZeroDivisionError: division by zero

捕获异常:

这里只输出提示信息:

#!/usr/bin/env python
# encoding: utf-8
"""
@author: kamil.liu @file: except.py
@time: 16-5-30 上午11:40
"""
x = 3
y = 0
try:
    print(x/y)
except ZeroDivisionError:
    print(The second number can`t be zero)

结果:

/usr/bin/python3.5 /home/kamil/PycharmProjects/untitled/test1/try/except.py
The second number can`t be zero

Process finished with exit code 0

不加参数,捕获异常:

如果捕获到异常,不处理,只传递异常,可以调用不带参数的raise,如下事例:

传递异常:

#!/usr/bin/env python
# encoding: utf-8

class MuffledCalculator:
    muffled = False
    def calc(self,expr):
        try:
            return eval(expr)
        except ZeroDivisionError:
            if self.muffled:
                print("Division by zero is illegal")
            else:raise
calculator = MuffledCalculator()
print(calculator.calc(9/3))
#calculator.muffled = True
print(calculator.calc(9/0))

"""
/usr/bin/python3.5 /home/kamil/PycharmProjects/untitled/test1/try/except.py
3.0
Traceback (most recent call last):
  File "/home/kamil/PycharmProjects/untitled/test1/try/except.py", line 16, in <module>
    print(calculator.calc(‘9/0‘))
  File "/home/kamil/PycharmProjects/untitled/test1/try/except.py", line 8, in calc
    return eval(expr)
  File "<string>", line 1, in <module>
ZeroDivisionError: division by zero

Process finished with exit code 1
"""

不传递异常

#!/usr/bin/env python
# encoding: utf-8

class MuffledCalculator:
    muffled = False
    def calc(self,expr):
        try:
            return eval(expr)
        except ZeroDivisionError:
            if self.muffled:
                print("Division by zero is illegal")
            else:raise
calculator = MuffledCalculator()
print(calculator.calc(9/3))
calculator.muffled = True
print(calculator.calc(9/0))

"""
/usr/bin/python3.5 /home/kamil/PycharmProjects/untitled/test1/try/except.py
3.0
Division by zero is illegal
None

Process finished with exit code 0
"""

除0行为发生,屏蔽被打开,calc会返回None。

 

Python3 捕捉异常

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原文地址:http://www.cnblogs.com/kamil/p/5542101.html

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