做网站有什么框架,个人网站构建,营销网络世界地图,手机网站建设策划书本文转载自公众号“读芯术”(ID#xff1a;AI_Discovery)。写代码必然会出现错误#xff0c;而错误处理可以针对这些错误提前做好准备。通常出现错误时#xff0c;脚本会停止运行#xff0c;而有了错误处理#xff0c;脚本就可以继续运行。为此#xff0c;我们需要了解下…本文转载自公众号“读芯术”(IDAI_Discovery)。写代码必然会出现错误而错误处理可以针对这些错误提前做好准备。通常出现错误时脚本会停止运行而有了错误处理脚本就可以继续运行。为此我们需要了解下面三个关键词try这是要运行的代码块可能会产生错误。except如果在try块中出现错误将执行这段代码。finally不管出现什么错误都要执行这段代码。现在我们定义一个函数“summation”将两个数字相加。该函数运行正常。defsummation(num1,num2):print(num1num2)summation(2,3)5接下来我们让用户输入其中一个数字并运行该函数。num12num2input(Enter number: )Enter number: 3summation(num1,num2)print(Thisline will not be printed because of the error)---------------------------------------------------------------------------TypeError Traceback (most recent call last)in----1 summation(num1,num2)2 print(This line will notbe printed because of the error)in summation(num1, num2)1 def summation(num1,num2):----2 print(num1num2)TypeError: unsupported operand type(s) for : int and str“TypeError”错误出现了因为我们试图将数字和字符串相加。请注意错误出现后后面的代码便不再执行。所以我们要用到上面提到的关键词确保即使出错脚本依旧运行。try:summed2 3except:print(Summation is not ofthe same type)Summation is not of the same type可以看到try块出现错误except块的代码开始运行并打印语句。接下来加入“else”块来应对没有错误出现的情况。try:summed2 3except:print(Summation is not ofthe same type)else:print(There was no errorand result is: ,summed)There was no error and result is: 5接下来我们用另外一个例子理解。这个例子中在except块我们还标明了错误类型。如果没有标明错误类型出现一切异常都会执行except块。try:fopen( test , w )f.write(This is a testfile)except TypeError:print(There is a typeerror)except OSError:print(There is an OSerror)finally:print(This will print evenif no error)This will print even if no error现在故意创造一个错误看看except块是否与finally块共同工作吧!try:fopen( test , r )f.write(This is a testfile)except TypeError:print(There is a typeerror)except OSError:print(There is an OSerror)finally:print(This will print evenif no error)There is an OS errorThis will print even if no error【责任编辑赵宁宁 TEL(010)68476606】点赞 0
