elegant smoking

For beginners, objective-C has a lot of confusing statements, but they are actually very elegant. What programmers write most are functions and functions written by themselves or written by others. This article describes the elegance of objective-C from the perspective of functions.C # and objective-C belong to the C series language. Let's take a look at the definition and call of C # functions for comparison.C # Function Definition:Public void doit (

what if I = = 0: #开头, to spell the left curly brace If Len (obj) = = 1:yield ' {%s:%s} '% (k, v) else:yield ' {%s:%s,\n '% (k, v) elif i = = Len (obj)-1: #结尾, spell right curly brace yield '%s%s:%s} '% (indent, K, v) else: #中间 yield '%s%s:%s,\n '% (indent, K, v) print '. Join (_pretty (obj, indent)) d = {"root": {"fol Der2 ": {" item2 ": None," Item1 ": none}," Folder1 ": {" Subfolder1 ": {" item2 ": None," Item1 ": none}," Subfolder2 ": {" ite M3 ": None}}}}pretty_Dict (d)

button on main interface B to exit the entire app, you will need to turn off the B-h-g-b-f-e-d-c-b-a interface in turn. And then the egg ... No one wants to shut it off like this. But let's assume that the B interface (main interface): Android:launchmode= "Singletask", then the boot process from a->b->c->d->e->f->b to the B interface, This is not another time to create a B interface, but the initiative to finish off the C, D, E, F interface and then use the original B interface. And then from t

tamper with the Func? also need to capture the func parameter args. So we wrap it with another function.Because the function is a class citizen, we can define the function inside the function. This is the most commonly used form of definition for adorners, in the following form1 def Deco (func): 2 def Newfunc (*args, * *Kwargs) :3 func (*args, * *Kwargs )4 returnWhere *args, **kwargs is used to capture parameters.We need to output the information before and after the funct

Since python2.6, a new function Str.format () that formats the string has been added to the power. So, what's the advantage of being compared to the previous% format string? Let us uncover the veil of its shy.GrammarIt replaces% with {} and:.Map sampleBy location字符串的format函数可以接受不限个参数，位置可以不按顺序，可以不用或者用多次，不过2.6不能为空{}，2.7才可以。通过关键字参数通过对象属性通过下标有了这些便捷的“映射”方式，我们就有了偷懒利器。基本的Python知识告诉我们，list和tuple可以通过“打散”成普通参数给函数，而dict可以打散成关键字参数给函数（通过和*）。所以可以轻松的传个list/tuple/dict给format函数。非常灵活。Format qualifierIt has a rich

'); Titleele.innerhtml=store.getstate (). Title.text; TitleEle.style.color=store.getstate (). Title.color; TitleEle.style.fontSize=store.getstate (). fontSize;}functionrendercontent () {Let Titleele=document.queryselector ("#content"); Titleele.innerhtml=store.getstate (). Content.text; TitleEle.style.color=store.getstate (). Content.color; TitleEle.style.fontSize=store.getstate (). fontSize;}functionRenderapp () {rendertitle (); Rendercontent ()}//Modify the appstate inside the initial value,

; } varJsonconverttype = Jsonnetassembly.gettype (Jsonnetjsonconverttypename,false); if(Jsonconverttype = =NULL) { return; } Serializefunc=Createserializeobjectfunc (Jsonconverttype); Deserializefunc=Createdeserializeobjectfunc (Jsonconverttype); Jsonnet.issupported= Serializefunc! =NULL Deserializefunc! =NULL; } /// ///to create a delegate for the SerializeObject method/// /// JsonConvert Type /// Private StaticfuncObjec

1. Convert the date format to a timestampGet current time: Currenttime= 'date'+%y-%m-%d%h:%m:%s' Result: 2015-04-13 11:15:43Convert current time to timestamp: timestamp= 'date'$curtime ' +%s ' Result: 1428894966　2. Convert the timestamp to a date format Convert the current timestamp to a date format: D ate -D " 1970-01-01 UTC $timestamp seconds " +%f "Result: 2015-04-13 date -D " 1970-01-01 UTC $timestamp seconds " +%f%T result: 2015-04-13 11:16:06 Date " 1970-01-01 UTC 142888717

="None"/> Three, the use method of PagehelperPagehelper.startpage (Pagenum, pageSize) only works with one of its most recent queries, more information related to paging we can get in the Page object, can meet the various cases of paging query.@TestpublicvoidtestQueryUserListthrows Exception { int pageNum=1; int pageSize=10; PagestartPage(pageNum, pageSize); userDao.queryUserList(); System.out.println("总共条数："+page.getTotal()); for (User user :

In the flower language, cherry blossom is the symbol of love and hope, in some specific festivals (Valentine's Day, Tanabata, etc.), if there are cherry blossom effect of the text embellishment, the whole page feels different. Share today's tutorial to teach students how to use Photoshop to create a fresh and elegant cherry blossom effect font, learn about it. 　Final effect: If you are interested to see here, then you may wish to analyze

the PDB module to set breakpoints in the script to debug the script, just like this: Import PDBPdb.set_trace () You can add pdb.set_trace () anywhere in the script, and the function will set a breakpoint in that position. Super convenient. You should read more about the PDB function, because there are a lot of little-known features in it. Simplifying If structure If you must check some values, you can use the if n in [1,4,5,6]: Rather than using a complex if structure: If N==1 or n==4 or

Blue has long been favored by internet companies, such as Facebook, Twitter, and so on. Blue is naturally cool, can give people a sense of security, but it also has a graceful and lively side, in many areas can be used, today to share a group of elegant blue Web site, hoping to bring you inspiration: Realtii Lander APP Blue Acorn Fork CMS Dynado Tomas Pojeta W3

@classmethod annotation method, will pass the class itself as a parameter, the advantage is that I can not invade the original code for function operationThe context management function, __enter__ and __exit__ functions, can be used to define the methods that are executed when using the method that executes when entering the function and the Exit function, where the WITH keyword is used to invoke the function.The classic scenario is to make the file read, using the WITH function to ensure that

elements and inserts elements quickly6. Sequence Unpacking:' Vttalk ' ' female ' ' [email protected] ' = P7 . Traverse the dictionary key and value for inch D.iteritems (): Note: Iteritems returns an Iterator object, only the items method in Python3, equivalent to Iteritems Print ' ---> ', V8. Chain comparison operation: If Guess:>>> false = = False = = True (The answer is: false)9,if/else three mesh operation:' male ' if ' male ' Else ' female '10, truth value judgment:if If attr = = True:if

First up.Which is the logo mark,is the picture to be detected.The code is as follows.#coding =utf-8import cv2import scipy as Spimg1 = Cv2.imread (' x1.jpg ', 0) # QueryImageimg2 = Cv2.imread (' x2.jpg ', 0) # Trainim age# Initiate SIFT detectorsift = Cv2. SIFT () # Find the keypoints and descriptors with SIFTkp1, des1 = Sift.detectandcompute (img1,none) kp2, des2 = Sift.detectand Compute (img2,none) # FLANN parametersflann_index_kdtree = 0index_params = dict (algorithm = flann_index_kdtree, tree

How do we refresh the output in the same row?The answer is carriage return .Note that the carriage return is not the same thing as a newline.Enter: Moves the current cursor to the beginning of the line. (\ r, return, CR, carriage return)Line break: The cursor position is unchanged, changing to the next line. (\ n, newline, LF, line Feed)The previous memory is very expensive, some people think the end of each line plus 2 characters too wasted, add one on the line. This results in a slightly diffe

According to test instructions, we can't use keywords such as if/else/for/while.------------in--------------thinkingIdeas:1. Recursive implementation of loops2. Recursive termination conditions do not use if how to judge it? The answer is a dictionary in which the number n is converted to bool with not not n.On the code:def sum_ (n): return n + { True:lambda:sum_ (n-1), false:lambda:0 }[not not n] () print sum_ (100)Elegant