Python

Here is my collection of some Python tips, is mainly a number of practical functions, suitable for a certain basis of children's shoes to watch (will not specifically describe the use of the standard library functions). One, function-type

#and or not#优先级 () >not>and>or# and or not Print and or and or and 3)# true or true or False# TruePrint(3>4or4 and1==1)#FalsePrint(1 and3or1>2)#TruePrint(2>1 and3or4>5 and2#TruePrint(1>2 and3or4>5 and2>1or9#FalsePrint(1>1

The SYS module is an interface that interacts with the Python interpreter.SYS.ARGV command line argument list, the first element is the path of the program itself.Sys.exit (n) exits the program, exits normally exit (0), error exits Sys.exit

---restore content starts---To learn a new programming language, you need to know what it can do.Now that we're going to learn python, let's get to the next python!.What is Python?Python is a high-level scripting language that combines explanatory,

This is once in Goku answer question, and later the effect is good, so issued, which combines the learning experience of the year and some industry teacher's advice, hope to help more interested people. (3rd benefit)Python language in recent years

First, define the functiondef function name (argument list): function bodydef function (): PassSecond, formal parameters/actual parametersX, y is the parameter, the memory unit is allocated only when it is called, and the allocated memory

This problem requires a hash to find the O (n) time complexity of key, otherwise it will time outInitialize a hash table \ Dictionary of DICThe head pointer start is initially 0The current pointer cur is initially 0Maximum length variable L is

Hashlib ModuleThe hashlib in Python provides us with a common digest algorithm, such as MD5, SHA1So now the question is, what is the abstract algorithm ? Abstract the algorithm is also called hash algorithm and hashing algorithm.It refers to the

A test.py file is defined first, then a function is defined and run directly after the function definition:test.pydef HaveFun(): if __name__ == ‘__main__‘: print(‘I am in my domain,my name is %s‘ % __name__) else: print(‘Someone else calls me!,my

Demand:STR1 = """ "br/>R/>n class= "Pt_title s_txt2" > Company: Location: Jiangsu, Yangzhou "" ""Want to remove all the tags of this string, such as removing , , Keep only the content without <>, but keep the Is there any good way to do it?

Summary of scheduling and running principles for processes, threads, and co-routines.Introduction to scheduling policies for processes and threadsLinux operating system detailed scheduling policy can be consulted:

Python installation1, download and unzip PYTHON-3.6.2.TAR.XZ2,tar XVJF Python-3.6.2.tar.xz2./configure--prefix=/usr/local/python33.make4.make Install5. Add Environment variablesVi/etc/profileAdd on last lineExport path= "$PATH:/usr/local/python3/bin"

Queue queues: Use import queue, same usage as process queueImport Queuequeue. Queue () #先进先出Q=queue. Queue (3) #设置队列长度为3, if put more than three programs will blockq.put (1)q.put (2)Q.put (3)print (Q.get ())print (Q.get ())Print (Q.get ())Results:123

One: Two ways to open a process (* * * * *) fromMultiprocessingImportProcessImport TimedefTask (name):Print('%s is running'%name) Time.sleep (3) Print('%s is done'%name)#on the window system, the operation to turn on the subprocess must be placed

R: Represents the handling of non-escaping phenomenaIn Python, u represents a Unicode string that is encoded using Unicode, no U represents a byte string, and the type is str, and is ASCI encoded by default when no encoding is declared. If you want

1, simple multi-threaded exampleImport Threading,timedef b_fun (i): Print "____________b_fun start" Time.sleep (7) Print "________________b_fun End"Def a_fun (): Print "__________a_fun start" t = Threading. Thread (Target=b_fun, args=

1.lxml is the parsing library, you need to import the package, directly in the command line input: PIP3 install lxml, basically will error. Correct should go to the corresponding URL: https://pypi.org/project/lxml/#files, directly download the

1.timeit Python standard library comes withThe algorithm is as follows: Loop the Code multiple times (parameter name number) so that it is long enough to have statistical time. Loop through Step 1 multiple times (parameter name repeat)

Map () functionApply the ' function ' method to each element in the ' iterable ' of the iterated function and return the result as a list.Here's an example:>>> def ABC (A, B, c): ... returnA * 10000 + b*+ C ... >>> list1 = [One, one, one] >>> list2 =

Multiprocessing Module IntroductionMultithreading in Python does not take advantage of multicore advantages, and if you want to fully use the resources of multicore CPUs, Os.cpu_count can view the number of logical CPUs, most of which require