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The shelve module is a simple k,v module that persists memory data through a file and can persist any Python data format that pickle can supportThe key is to support multiple read and write and change operationsSerialization:Import Shelvef= Shelve. Open(' Shelve_test ')# Open a file names=["Alex","Rain", "test" ]info = { ' name ' : ' Alex ' , ' age ' ] = Infof .close ( Deserialization:import shelved = shelve.open(‘shelve_test‘) # 打开一个文件print(d[‘name

A concise explanation of the use of sys.argv[] in PythonBecause it is reading self-taught python, began soon after the introduction of the module function, and has been on the idle edit after the run, trying to find its use from the results, but the results have been no results, but also on the internet a lot, but found that the problem of a more detailed explanation of only one version, Most of them are transferred and copied. Give is a concise

The address series should be af_inet (the default), Af_inet6,af_unix,af_can or af_rds.(The Af_unix domain is actually using a local socket file to communicate) Type The socket type should be SOCK_STREAM (the default), Sock_dgram,sock_raw, or one of the other Sock_ constants.Sock_stream is a TCP-based, guaranteed (that is, the data is guaranteed to be transmitted correctly to each other) socket for connection, which is used for data transmission.sock_dgram is a UDP-based

:Print ("Welcome User{name} Login ...". Format (name=username))ElsePrint ("Invalid username or password")Old_of_boy = 56#guess_age =int (Input ("Pesse input Age:") is the correct representationCount = 0While countCount = count + 1 # equivalent to count + = 1guess_age = Int (input ("please"))If Guess_age==old_of_boy:Print ("Yes.") You get It ")BreakElif Guess_age>=old_of_boy:Print ("Think bigger!")ElsePrint ("Think smaller!")‘‘‘For I in Range (0,10): #开始 End step Contimue end this loop brea

For the first day of the course outline, the left for the understanding of the section, the right needs to focus on and practice (hand-hit).Exercises: using while loop input 1 2 3 4 5 6 8 9 1 count=12 while count: 3 print (count) 4 if count ==6: 5 count +=16 print ( " " Span style= "COLOR: #000000" >) 7 count +=18 loop output the sum of all the numbers for 1-100 and 1 count = 12 sum =3 while count: 4 sum= sum + count 5 count= count + 16 print (sum) 1-10

777g = Funcl ()Print (g)Conclusion: # Analytical:First: As long as there is yield in the function, he is not a function, but a generator.Second: G is called the generator objectPerform:Print (g.__next__ ())Print (g.__next__ ())Print (g.__next__ ()) #超出yield数量, errorThe role of sentNext, like the Send function, is performed onceSend can assign a value to the previous yieldCases:Def generator ():Print (123)Content = Yield 1Print (content)Print (456)Yield 2g = Generator ()G.__next__ ()G.send (' He

.__iter__function, includeRangealso have. OK?? Try?Under.In comprehensive.We can be sure.if the object has__iter__function. Then we think this object adheres to the iterative protocol this __iter__ we make? __next__ () to get the element in an iterator So what we said earlier for What is the principle? continue to see code ? . ? BuilderWhat is the builder . The Builder is essentially an iterator . There are three ways to get the generator in

expressed as (√￣), such as: The Mathematical language is: √￣16=4. The language is described as: 16=4 under the square root.The following example enters a number by the user and calculates the square root of the number:‘‘‘Print (' The square root of this number is:%.9f '% (float (input (' Enter a number: ')) * * 0.5))Knowledge Point One: the reciprocal of the square root to powerThe arithmetic formula is num_sqrt=num**0.5Extension code#定义输入数字为字符串num= Float (input ' Enter first number: ')#告诉运算公式N

Named rules:Project name Package name python file name1. Cannot start with a number, cannot use Chinese2. Cannot use keywords3. English Letter Test_06_234. Alphanumeric underline (cannot start with a number)5. See the name of knowing ageVariable:x = 1 #定义一个变量x, and is assigned a value of 1Print (x) #如果要引用某个变量 to ensure that the variable has been assigned a defined valueCommon data types: shaping floating-point Boolean stringsage = #关键字 intScore = 99.9

) +" "A string is required to connect #使用 + number - Job:" "+job+" " - Salary:" "+Salary the Print(Info) - -Info2 =" " - ------------Info2 of%s------------ + name:%s - age:%d + job:%s A salary:%s" "%(name,name,age,job,salary) at Print(Info2) - -Info3 =" " - ------------Info3 of {_name}------------ - Name:{_name} - Age:{_age} in Job:{_job} - Salary:{_salary}" ". Format (_name=name,_age=age,_job=job,_salary=salary) to + Print(INFO3) - theInfo4 =" " * ------------Info4 of {0}------------ $ name

queue. Q.full (): When this method is called, Q is full to return true, and the result is unreliable, for example, in the process of returning true, if the items in the queue are taken away. Q.qsize (): Returns the correct number of current items in the queue, and the results are unreliable, for the same reason as Q.empty () and Q.full ()Application:#队列 # 1. You can put any type of # 2 into the queue. FIFO from multiprocessing import process,queueq= Queue (3) q.put (' first ') #默认block =trueq.

Get Request:Usage Scenario: If you only get data for the server and do not have any impact on the server, then use a GET request at this time . parameter:The Get request is placed in the URL , and is passed '? ' To specify key and value in the form of the Post Request:Usage Scenario: If you want to have an impact on the server, use the post requestReference:the post request parameter is not placed in the URL , it is sent to the server via ' form data 'Get and post requests get parameters:Get re

table name (column name ()) #index_name is the key_name is not related to the original table arbitrarily setCreate INDEX index_name on student (name (32))Modify Table Structure AdditionsAlter student Add index index_name on (column name ())CREATE TABLE AdditionsCREATE TABLE student (ID int not NULL, index index_name (column name (length)))CREATE TABLE student (ID int not NULL, index Index_name (name (32))); ************Delete IndexDrop index index_name on table name; Show index from studentDrop