surf cookbook

errorTraceback (most recent): File"", Line 1,inchIndexerror:index out of range>>> Heappush (a,3)>>>a[3]>>> Heapreplace (a,2)#Delete (Heappop (a)->3) first, then join (Heappush (a,2))3>>>a[2]>>> Heappush (a,5) >>> Heappush (a,9)>>> Heappush (a,4)>>>a[2, 4, 9, 5]>>> Heapreplace (a,6)#first find the minimum value from heap A and return, then add 62>>>a[4, 5, 9, 6]>>> Heapreplace (a,1)#1 is added later, before 1, the minimum value in a is 4 .4>>>a[1, 5, 9, 6]>>> a=[2,4,6] >>> b=[1,3,5]>>>

Problem: You want to access the element by name to reduce the dependency on the location in the structureSolution: Use the named Tuple collections.namedtuple (). It is a factory method that returns a subclass of the standard tuple type in Python, gives it a type name and the corresponding field name , returns a class that can be instantiated, gives you a defined field name to pass in the value, and so on.The primary purpose of a named tuple is to decouple the code from the location of the elemen

Problem: Want to create a dictionary, which is itself a subset of another dictionarySolution: Use dictionary derivation (dictionary comprehension) to easily solve#example of extracting a subset from a dictionary fromPprintImportpprintprices= { 'ACME': 45.23, 'AAPL': 612.78, 'IBM': 205.55, 'HPQ': 37.20, 'FB': 10.75}#Make A dictionary of pricesP1 = {Key:value forKey, ValueinchPrices.items ()ifValue > 200 }Print("All prices") Pprint (p1)#Make A dictionary of tech stocksTech_names = {'AAPL

=min (Zip (Prices.keys (), Prices.values ())) #zip () parameter is incorrect in order to get the wrong value>>>Min_price3 ('AAPL', 612.78)>>> Max_price3 =max (Zip (Prices.keys (), Prices.values ())) #zip () parameter is incorrect in order to get the wrong value >>>Max_price3 ('IBM', 205.55)>>>When doing these calculations, note that zip () creates an iterator whose contents can only be consumed once. For example:>>> pirces_and_names=Zip (prices.values (), Prices.keys ())>>> pirces_and_names mi

If the object is an iterative (any sequence), it can be decomposed, including tuples, lists, strings, files, iterators, and generators, which can be decomposed into separate variables by a simple assignment operation.The only requirement: The total number of variables matches the sequence, otherwise an error will occur;Python 2.7.11 (v2.7.11:6d1b6a68f775, Dec 5, 20:32:19) [MSC v.1500 32bit (Intel)] on Win32type"Copyright","credits" or "license ()" forMore information.>>> p=[4,5]>>>p[4, 5]>>> x,

experimentImportunicodedatan_s1= Unicodedata.normalize ('NFC', s1) n_s2= Unicodedata.normalize ('NFC', S2)Print('n_s1 = = n_s2?', n_s1 = =n_s2)Print('len (n_s1) =', Len (N_S1),'Len (N_S2)', Len (n_s2))Print('*****************************')#(d) Example of normalizing to a decomposed form and stripping accentsT1 = Unicodedata.normalize ('NFD', s1) T2= Unicodedata.normalize ('NFD', S2)Print('T1 = = t2?', t1==T2)Print('len (t1) =', Len (T1),'len (t2) =', Len (T2))Print("'. Join (c forCinchT1if not

keyword;#example.py##Example of combining text via generatorsdefsample ():yield " is" yield "Chicago" yield " not" yield "Chicago?"#(a) use Join () to simply connect them togetherText ="'. Join (sample ())Print(text)Print('======================')#(b) Redirect these fragments to I/OImportSYS forPartinchsample (): Sys.stdout.write (part) Sys.stdout.write ('\ n')Print('**************************')#(c) intelligently combine I/O operations in a mixed mannerdefCombine (source, maxsize): Par

(Datepat.sub (change_date, text))Print(Re.sub (R'(\d+)/(\d+)/(\d+)', Change_date, text))Print('++++++++++++++++++++++++++++++++')# Total number of replacements obtained by RE.SUBN () newtext,n =datepat.subn (r " \3-\1-\2 " , text) print (NewText) print (N) >>> ================================ RESTART ================================>>> yeh,but No, But yeh,but no,but yeh,but no,but yehyeah,but yes,but yeah,but yes,but yeah,but no,but yeah------------------------- - -is 2012-11-27. Pycon

Python cookbook (data structure and algorithm) method for saving the last N elements, pythoncookbook This example describes how to save the last N elements in Python. We will share this with you for your reference. The details are as follows: Problem:We hope to make a limited history statistics for the last few records during iteration or other forms of processing. Solution:Select collections. deque. The following code performs a simple text match on

Class and object of the 8th chapter 2016.5.38.1 Changing the object's string display __str__ and __repr__%s and%r, mentioned Eval, I didn't use it.8.2 Formatting a custom string __format__8.3 Let the object support context management, __enter__ and __exit__, you can use the WITH8.4 Ways to save memory when creating a large number of objects __slot__,__slot__ is more of a memory-optimized tool than a wrapper tool to prevent users from adding new properties to an instance.8.5 Encapsulating propert

(processingtasks);}Alternatively, this can written as:Static Asynctaskint> Delayandreturnasync (intval) { awaitTask. Delay (TimeSpan. FromSeconds (Val)); returnVal;}//This method is now prints "1", "2", and "3".Static AsyncTask Processtasksasync () {//Create a sequence of tasks.taskint> Taska = Delayandreturnasync (2); Taskint> TASKB = Delayandreturnasync (3); Taskint> TASKC = Delayandreturnasync (1); vartasks =New[] {Taska, TASKB, TASKC};varProcessingtasks = tasks. Select (Asynct = { varresult

Smooth python and cookbook Study Notes (7), pythoncookbook1. Read and Write compressed data files Use the gzip and bz2 modules to read and write compressed files. However, pay attention to the file mode. The default format is binary. 1 # Read the compressed file 2 import gzip 3 with gzip.open('somefile.gz ', 'rt') as f: 4 text = f. read () 5 6 import bz2 7 with bz2.open('somefile.bz2 ', 'rt') as f: 8 text = f. read () 9 10 # Write compressed data 11

Smooth python and cookbook Study Notes (6), pythoncookbook1. iterate multiple sequences at the same time (zip (function )) You can use the zip () function to iterate multiple sequences at the same time. >>> X = [1, 2, 3, 4, 5, 6]>>> Y = [121, 223, 116, 666, 919, 2333]>>> for x, y in zip(X, Y):... print(x, y)...1 1212 2233 1164 6665 9196 2333 Zip (a, B) is used to create an iterator that generates tuples (x, y), x is taken from sequence a, and y is

Framework Framework specification. If X. Equals (y), then X. GetHashCode () and Y. GetHashCode () should return the same value, which in turn is not required (if X. GetHashCode () and Y. GetHashCode () returns the same value, X. Equals (y) can return false), and X and Y can also share a hash code when they are not equal. In our entity base class, we simply use the hash code value of the ID.Supplemental knowledgeFor more knowledge about equals and GetHashCode, see the MSDN documentation for Http

The n elements are decomposed from an iterative object, but the length of an iterative object may exceed N, and an exception of "too many decomposition values" appears.Use "* expression" to resolve the problem:Python 3.4.3 (v3.4.3:9b73f1c3e601, Feb, 22:43:06) [MSC v.1600 32bit (Intel)] on Win32type"Copyright","credits" or "license ()" forMore information.>>> *headdata,current=[10,3,2,6,8,5]#* Modified variables are located in the first position of the list, easy to separate head and tail>>>head

) print "Sent:%d characters, so far ..."%sent_data_length # Display Server re Sponse response = SELF.SOCK.RECV (buf_size) print "PID%s Received:%s"% (Current_procESS_ID, Response[5:]) def shutdown (self): "" "Cleanup the Client Socket" "" Self.sock.close () Class Forkingserverrequesthandler (Socketserver.baserequesthandler): def handle (self): # Send the echo back To the client data = SELF.REQUEST.RECV (buf_size) current_process_id = os.getpid () response = '%s:%s '% (current_process_id, data)

();　　Double deltat=t1-t0; System.out.println (Decimalformat.getinstance (). Format (deltat/1000.) + "seconds.");　Import java.io.*;　　Import java.text.*; /** * Timer for processing sqrt and I/O operations */public class timercompution{public static void Man (string[]　　　　args) {try{new Timer (). run ();　　}catch (IOException e) {System.err.println (e);} } public void Run () throws ioexception{DataInputStream n=new DataOutputStream (New Bufferedoutputstream (New File　　　　　　OutputStream (Sysdep.getde

Title: Web Cookbook Multiple SQL InjectionAuthor: Saadat Ullah, saadi_linux@rocketmail.com: Http://sourceforge.net/projects/webcookbook/Home: http://security-geeks.blogspot.com/Test System: Server: Apache/2.2.15 (Centos) PHP/5.3.3# SQL InjectionHttp: // localhost/cook/searchrecipe. php? Sstring = [SQLi]Http://www.bkjia.com/cook/showtext. php? Mode = [SQLi]Http: // localhost/cook/searchrecipe. php? Mode = 1 title = [SQLi] prefix = preparation = pos

ConceptThe asynchronous function (asynchronous funcation) is a higher level abstraction above the TPL, which really simplifies asynchronous programming. Abstraction hides the main implementation details, allowing programmers to make asynchronous programming easier without having to consider many important things.More contentTo create an asynchronous function, first annotate a method with the Async keywordNote: This article is read in the "C # multithreaded Programming Combat" after the written,

(interruptedexception e) {e.printstacktrace (); } System.out.printf ("Network connection has finished:%s\n", NewDate ()); } }If you run this sample program multiple times, you will find that the main thread will not end until you run the Thread1 and end before running thread2,thread2 ends.The join () method has two similar methods, respectively:(A) Join (long milliseconds)(B) Join (long milliseconds, long Nanos)These two methods lead to the end of the thread that will suspend