如何在PYTHON里捕获和抛出异常

1、result = int(input("What is the result when 1 plus 1?"))#这里需要用户输入整数，但是这里却是字符，那么就显示出错。

2、try: result = int(input("What is the result when 1 plus 1?&鳎溻趄酃quot;))except: print("The value is wrong!")except Exception as i: print("This is unknow error %s. " % i)print("The end!")#如果不知道还会有什么异常可以用Exception，但是这里出错是因为单独except要放在后面。

3、try: result = int(input("What is the result when 1 plus 1?"))except Exception as result: print("This is unknow error %s. " % result)except: print("The value is wrong!")print("The end!")#这个时候就可以排除所有错误了。

4、try: result = int(input("What is the result when 1 plus 1?"))except Exception as result: print("This is unknow error %s. " % result)else: print("No error!")finally: print("The end!")#可以在后面加上else，如果没有错误就会运行，形成try...else语句。

5、try: result = int(input("What is the result when 1 plus 1?"))except Exception as result: print("This is unknow error %s. " % result)else: print("No error!")finally: print("The end!")#但是如果有异常else不会运行。但是finally是会运行的。

6、def test1(): return int(input("What is the result when 1 plus 1?"))test1()#这里可以看出发现异常系统没有马上终止，而是先进行传递。

7、def test1(): return int(input("What is the result when 1 plus 1?"))try: test1()except Exception as result: print("somthing is wrong %s. " % result) #面对这种情况也是可以在最后面加上try和except来捕获异常。

8、def test(): result = int(input("What is the result when 1 plus 1?")) if result.isalpha(): return result print("there is an error.") error = Exception("输入错误") raise error test()#我们可以主动捕获异常。

9、def test(): result = input("What is the result w茑霁酌绡hen 1 plus 1?") if len(result) == 1: return result print("there is an error.") error = Exception("输入错误") raise errortry: print(test())except Exception as result: print(result) #设置try和except在下方，然后正常运行一下。

10、def test(): result = input("What is the result w茑霁酌绡hen 1 plus 1?") if len(result) == 1: return result else: print("there is an error.") raise Exception("输入错误")try: print(test())except Exception as result: print(result)#这个时候就可以在有错误的时候捕获到异常。先运行，有错误的话捕获异常，并且在except里面把异常当结果输出。