try语句是python里面的控制语句,与except,finally配合使用处理在程序运行中出现的异常情况。
try的工作原理是:当开始一个try语句后,python就在当前程序的上下文中作标记,这样当异常出现时就可以回到这里,try子句先执行,接下来会发生什么依赖于执行时是否出现异常。
假如在读一个文件的时候,希望在无论异常发生与否的情况下都关闭文件,该怎么做呢?这可以使用finally块来完成。注意,在一个try块下,可以同时使用except从句和finally块。如果要同时使用它们的话,需要把一个嵌入另外一个。
扩展资料:
python的基础语法
Python的设计目标之一是让代码具备高度的可阅读性。它设计时尽量使用其它语言经常使用的标点符号和英文单字,让代码看起来整洁美观。
python的用法
Python可以以交互模式运行,比如主流操作系统Unix/Linux、Mac、Windows都可以直接在命令模式下直接运行Python交互环境。直接下达操作指令即可实现交互操作。
一个和其他大多数语言(如C)的区别就是,一个模块的界限,完全是由每行的首字符在这一行的位置来决定的(而C语言是用一对花括号{}来明确的定出模块的边界的,与字符的位置毫无关系)。
参考资料来源:百度百科-Python
参考资料来源:python官网-try..finally
1、try的基本意思是“试用”“努力”,指为完成某工作或验证某事实的目的而付出努力或作出尝试,但不指冒险做某事。
2、try可作“考验”“磨炼”解,指用令人感到痛苦的人或事对某人的精神和肉体施加压力以测其忍耐力或自我控制力。
3、try还可作“审讯”“审理”解,指人的罪过与清白的证实过程,而非结论,也可表示“检验”事物的真伪、价值、强度与效力等。
4、try既可用作及物动词,也可用作不及物动词。用作及物动词时,可接名词、代词、动名词、动词不定式、wh-从句作宾语。
5、try可接同源宾语,其宾语在最高级形容词后常可省略。
6、try无须用非人称代词代替前面的整个句子。
7、try偶尔可接由动词不定式充当宾语补足语的复合宾语。
8、try and to/- v 与try to- v 意思基本相同,但try and to/- v 比try to- v 更带有迫切的意味,常用于口语,而try to- v 多用于书面语。try and to/- v 只能用于现在时、将来时、祈使句、过去时一般疑问句。
9、try用作名词时意为“尝试”,是可数名词,后可接由at或for引起的介词短语。
扩展资料
近义词:
一、attempt 英 [ə'tempt] 美 [ə'tempt]
v. 企图;尝试
n. 企图;试图
例:I would be the last to attempt to answer the question.
我是最不可能去尝试回答这个问题。
二、shot 英 [ʃɒt] 美 [ʃɑːt]
n. 注射;投篮;发射;拍摄;开枪;子弹
adj. (织物)闪色的;精疲力尽的;完了的
动词shoot的过去式和过去分词.
例:Eight-year-old Griffin Stevens made the shot of a lifetime this past weekend.
8岁的格里芬史蒂文斯在本周末创造了一次一生难忘的投篮。
“try-catch-finally语句块”用来捕获并处理异常。
你可能会想,如果你写程序的时候有意的去避免异常,那么“try-catch-finally语句块”不就没什么用了吗?可是,你的程序不是给你自己使用的吧?如果你要求用户输入1个数字,而且你的程序也明确提示了用户需要输入的是数字,但用户就是输入了“英文字母”,那么,你的程序没有“try-catch-finally语句块”一定会直接崩溃的。而如果用了“try-catch-finally语句块”,并将这个异常处理为“再次提醒用户需要输入的是数字,并再次允许用户重新输入”,那你的程序就不会半途挂掉。
【示例】
//用"try-catch"强制用户必须输入一个数字!import java.util.Scanner;public class Test2 { public static void main(String args[]) { double d = 0; boolean badInput = true; Scanner input; while(badInput) { System.out.println("请输入1个数字:"); input = new Scanner(System.in); try { d=input.nextDouble(); } catch(Exception e) { System.out.println("您输入的不是数字!"); continue; } badInput = false; } System.out.println("您输入的是:" + d); }}
if else 是流程控制语句,try catch是异常处理语句。
1,if用来判断表达式返回的是true还是false,例如
if(a==b){ System.out.println("yes");}else{ System.out.println("no");}
不能使用try catch判断。
2,try catch是用来捕获异常的,这里的异常是指在程序运行时可能出现的异常,捕获异常后try里的代码将不再执行,而是转到catch里面执行。如果没有异常,则执行try里的代码,catch里面不用执行。例如
String a = "12211a"; try { int b = Integer.parseInt(a); // 将字符串转为数字,a里面有字母,转换失败,将会抛出异常。 System.out.println("is a number:"+b); } catch (Exception e) { System.out.println("not a number"); }
try { //可能会抛出异常的语句} catch(Exception e) { //对捕捉到的异常进行处理} finally { //不管有没有异常,都进行的操作}
Try to do sth----努力做某事。Try doing sth-----尝试做某事。try a fall with 与...较量一番try back 重新回到try conclusions with 和...决胜负try for 争取, 谋求, 申请try it on (对...)耍花招try on 试穿, 试验try one's best 尽力try sth out 试验, 考验, 提炼try out for sth参加。。。的选拔try over 试演(戏剧等)try to 设法try up 校准, 为...最后加工try your hand at sth 初试身手try one's luck 碰运气try sb 's patient 使不耐烦差不多就这些了可以参考下, 希望对你有帮助O(∩_∩)O~
Put your make-up on 化好妆 Get your nails done 美好甲 Curl your hair 卷上头发 Run the extra mile 再跑一英里 Keep it slim so they like you 保持苗条他们才会喜欢你 Do they like you? 他们喜欢你吗? Get your sexy on 秀出性感 Don't be shy, girl 女孩,不要害羞 Take it off 把腼腆收起 This is what you want, to belong, so they like you 这就是你想要的 Do you like you? 跟他们一样,他们才会喜欢你 You don't have to try so hard 你喜欢你自己吗? You don't have to 你不必如此勉强 give it all away 你不必放弃真我 You just have to get up, get up, get up, get up 你只需勇敢面对自己 You don't have to change a single thing 你无需做出任何改变 You don't have to try, try, try, try 你不必勉强 You don't have to try 你不必勉强 Get your shopping on, at the mall 去商场尽情购物 max your credit cards 把信用卡刷爆 You don't have to choose, buy it all 你不用选择,想买的都买下 So they like you 这样他们才会喜欢你 Do they like you? 他们喜欢你吗? Wait a second, 等等 Why, should you care, what they think of you 你为何要在意别人怎么看你 When you're all alone, by yourself, 当你独处时, do you like you? 你喜欢你自己吗? Do you like you? 你喜欢你自己吗? You don't have to try so hard 你不必如此勉强 You don't have to, give it all away 你不必放弃自我 You just have to get up, get up, get up, get up 你只需勇敢面对自己 You don't have to change a single thing 你无需做出任何改变 You don't have to try so hard 你不必勉强 You don't have to bend until you break 你不必勉强 You just have to get up, get up, get up, get up 你只需勇敢面对自己 You don't have to change a single thing 你无需做出任何改变 You don't have to try, try, try, try 你不必勉强 You don't have to try 你不必勉强 Take your make-up off 卸去妆容 Let your hair down 散开头发 Take a breath 吸一口气 Look into the mirror, at yourself 看看镜中的自己 Don't you like you? 你喜欢你自己吗? Cause I like you 因为我喜欢这样的你
C语言里try是一个语句或函数。其作用是是抛出错误用。 将有可能产生错误的语句括在一起,放入try语句块。如果在try语句块中发生异常,FlashPlayer会创建一个错误对象,并将该Error对象派发至第一个可用的catch块。catch语句块提供对错误的处理。如果没有try语句,或者try语句没有出现错误,则catch语句不会被引发。如果在try语句块的其中某个语句中检测到错误,则会执行附加到该try语句的catch语句。catch语句可以并列使用,即在一个try语句块之后,存在多个catch语句块,以处理不同的错误对象。 try语句是:try { do something } catch(some error) { do something }
Oooh哦~~·Oooh哦~~·Put your make up on 把你的化妆Get your nails done让你的指甲Curl your hair卷曲的头发Run the extra mile多跑一英里Keep it slim so they like you, do they like you?保持苗条,所以他们喜欢你,他们喜欢你吗?Get your sexy on让你的性感Don't be shy, girl不要害羞,女孩Take it off把它关掉This is what you want, to belong, so they like you这是你想要的,属于,所以他们喜欢你Do you like you?你喜欢你吗?You don't have to try so hard你不必着急You don't have to, give it all away你不必,放弃一切You just have to get up, get up, get up, get up你必须起床,起来,起来,起来You don't have to change a single thing你不需要改变任何事You don't have to try, try, try, try你不必尝试,尝试,尝试,尝试You don't have to try, try, try, try你不必尝试,尝试,尝试,尝试You don't have to try, try, try, try你不必尝试,尝试,尝试,尝试You don't have to try你不必尝试Yooou don't have to tryyooou不去尝试Oooh哦~~Oooh哦~~Get your shopping on, at the mall, extra credit card让您的购物,在商场,额外的信用卡You don't have to choose, buy it all, so they like you你没有选择,购买它,所以他们喜欢你Do they like you?他们喜欢你吗?Wait a second,等一等Why, should you care, what they think of you为什么,你应该关心,他们怎么看待你When you're all alone, by yourself, do you like you?当你独自一人,由你自己,你喜欢你吗?Do you like you?你喜欢你吗?You don't have to try so hard你不必着急You don't have to, give it all away你不必,放弃一切You just have to get up, get up, get up, get up你必须起床,起来,起来,起来You don't have to change a single thing你不需要改变任何事You don't have to try so hard你不必着急You don't have to, give it all away你不必,放弃一切You just have to get up, get up, get up, get up你必须起床,起来,起来,起来You don't have to change a single thing你不需要改变任何事You don't have to try, try, try, try你不必尝试,尝试,尝试,尝试You don't have to try, try, try, try你不必尝试,尝试,尝试,尝试You don't have to try你不必尝试You don't have to try你不必尝试You don't have to try, try, try, try你不必尝试,尝试,尝试,尝试You don't have to try, try, try, try你不必尝试,尝试,尝试,尝试You don't have to try, try, try, try你不必尝试,尝试,尝试,尝试You don't have to try你不必尝试Yooou don't have to tryyooou不去尝试NooooOoohYou don't have to try so hard你不必着急You don't have to, give it all away你不必,放弃一切You just have to get up, get up, get up, get up你必须起床,起来,起来,起来You don't have to change a single thing你不需要改变任何事You don't have to try, try, try, try你不必尝试,尝试,尝试,尝试You don't have to try, try, try, try你不必尝试,尝试,尝试,尝试You don't have to try你不必尝试You don't have to try你不必尝试