Python

#_ *_coding:utf-8_*_ "To create a SQLAlchemy application basic procedure 1, create a connection (and a relational database to create a connection) 2, declare a mapping file (Python-to-class and database tables do a one-to-one mapping, This allows

List installed Packagespip freezeor pip list Export Requirements.txtpip freeze > /requirements.txtinstallation package Online Installationpip install or pip install -r requirements.txt Specify the version by using = = >= The Requirements.txt

ProcessThe program does not run alone, only the program is loaded into memory, the system allocates resources to run, and this execution of the program becomes a process, program and process differences, the program is a set of instructions, it is a

The functions of the Calendar module are calendar-related, provide some ways to manipulate dates, and generate calendars.There are three main categories available in the Calendar module:First, calendar. Calendar (firstweekday=0)This class provides a

SocketSockets are also commonly referred to as "sockets," which describe IP addresses and ports, and are a handle to a chain of communication, where applications usually make requests to the network through "sockets" or respond to network

Programming language is mainly from the following angles for classification, compiled and interpreted, static language and dynamic language, strong type definition language and weak type definition language, what each category represents, let's take

The filter () function is another useful high-order function built into Python, and the filter () function receives a function f and a list, the function F of which is to judge each element, returning True or False,filter () Automatically filters

GitHub Address: Https://github.com/honmaple/maple-file A simple image upload service with flask implementation Design Intent For the storage of pictures, there are many choices, general use of cloud services such as (Seven Bull, and Pat,

First, Brief introduction Regular expressions are a small, highly specialized programming language that is not unique to Python and is a fundamental and important part of many programming languages. In Python, this is done primarily through the RE

This article mainly describes the Python image grayscale transformation and image array operation related data, the need for friends can refer to the following Use Python and NumPy to perform a series of basic image processing by manipulating the

In this paper, from the internal functions provided by the system, third-party provide function library + simple crawl code and install the HTTPLIB2 module process and user self-defined function three aspects to be narrated. Has a good reference

The formatting used in Python's pprint modules can be formatted to display data in a format that is parsed by the parser and is easy to read. The output is saved in a single line, but you can also use an indent representation when splitting multiple

This article mainly introduces Python to find out 9 consecutive free ports, the interested partners can refer to First, the project needs To install a software, configure the time to fill out the idle port. See if a port on one of 5 platforms is

The recent use of Python has encountered a number of pits, such as the Datetime.datetime.now () variable object as the default parameter of the function, the module cycle dependency and so on. Record here, convenient for later inquiries and

The string formatting operator (%) is very similar to the string formatting of the printf () function in C, and even the symbols used are the same, all with percent sign (%), and all printf () format operations are supported. The syntax is as

#!/usr/bin/env python#-*-coding:utf-8-*-if __name__ = = ' __main__ ':List = [' html ', ' js ', ' css ', ' python ']# method 1print ' Traverse list method 1: 'For I in List:Print ("ordinal:%s value:%s"% (list.index (i) + 1, I))print ' \ n Traverse

If a function calls itself directly or indirectly, it forms a recursive (recursion), such as an implementation of the Fibonacci Sequence.def fib (n): if n Recursion must have an end condition, otherwise a dead loop is formed, such as the

Server side:1 Create a Socket object. Call the socket Constructor. Such as:Socket = Socket.socket (family, Type)#family参数代表地址家族, can be af_inet or af_unix. The Af_inet family includes internet addresses, and the Af_unix family is used for

Python development [Chapter 28]: algorithm (II), chapter 28 of pythonHeap sorting 1.-tree and Binary Tree Introduction A tree is a data structure, such as a directory structure. A tree is a data structure that can be recursively defined. A tree is a

Python development [Chapter 28]: algorithm, chapter 28 of pythonAlgorithm Basics 1. What is an algorithm? Algorithm (Algorithm): a method for solving problems in a computing process   2. Review: Recursion Recursive features: Call itself End