【数据结构】-经典面试问题吐血整理
数据结构整体框架：https://blog.csdn.net/qq_39328436/article/details/114337675线性表 数组和链表的区别 从结构上：，数组和链表都是线性结构，但是，数组是一块连续的内存空间，链表可以是零散的内存空间，用指针连接 从操作上：数组能够实现按下标访问和修改，查找效率高，链表的查找效率低；数组的增加和删除需要移动元素，效率低，但是链表的增加和删除只需要修改指针，在o(1)时间内就能完成 从存储上：静态数组.
【组成原理】-经典面试题吐血整理
组成原理整体框架：https://blog.csdn.net/qq_39328436/article/details/114680942说明：本篇文章是笔者为准备研究生复试和校招而写，因此主要针对问答，注重理解，而不在于细节计算。读者可以先查看上面的链接走一遍组成原理的整体框架结构。其中，重点难点以及易混淆的知识点，笔者会用其他文章进行了详述，在知识点处贴好了链接，有需要的可以查阅。组成原理是校招系统概述四门计算机专业课之间的关系数据结构研究的是数据和操作这些数据的算法，属于软件层面。.
__name__详解
1.py作为入口运行总结，在一套python程序中，总有一个入口模块， 在入口模块打印__name__的值，为__main__,在其他模块打印__name__的值，值为当前模块名
flask框架之flask工程的搭建和配置
环境安装环境安装1. 复习虚拟环境和pip的命令2. 创建虚拟环境3. 安装FlaskHelloWorld程序1 目标2 思考3 Flask程序编写导入Flask类4 启动运行参数说明1 Flask对象初始化参数默认参数情况下修改参数的情况下2 应用程序配置参数作用使用方式读取设置项目中的常用方式3 app.run 参数开发服务器运行方式1 终端启动说明扩展2 Pycharm启动环境安装1. 复习虚拟环境和pip的命令# 虚拟环境mkvirtualenv # 创建虚拟环境rmvirtualenv
flask框架之路由与蓝图
路由@app.route("/itcast")def view_func(): return "hello world"1 查询路由信息命令行方式flask routesEndpoint Methods Rule-------- ------- -----------------------index GET /static GET /static/在程序中获取在应用中的url_map属性中保存着整个Flask应用的路由映
理解version of Python Package
OverviewMaybe the question in English is :How to define the version information about a Python package?Other questions to be favor for understanding:What is module and How to publish module in Python?There are many different schemes that can be ..
理解Shebang line: #!/usr/bin/python3
OverviewFrom google styleguide, Most .py files do not need to start with a #! line.Start the main file of a program with #!/usr/bin/env python3 (to support virtualenvs) or #!/usr/bin/python3 per PEP-394.This line is used by the kernel to find the Pyth..
理解Sphinx about Python docstring
OverviewFrom numpydoc, Numpy’s documentation uses several custom extensions to Sphinx, these are shipped in this numpydoc package, in case you want to make use of them in third-party projects.SphinxA sphinx is a mythical creature with the head of a ..
理解What is Unity and Game Engine and Sandbox
Game EngineA game engine, also known as a game framewokr, is a software-development environment designed for people to build video games.The core functionality typically provided by a game engine includes:a rendering engine for 2D or 3D graphicsa ph..
理解difference between Regression Analysis and Machine Learning
Overview查看Regression Analysis的定义时发现，Regression analysis is a set of statistical processes for estimating the relationship between a dependent variable and one or more independent variables.那这不就是机器学习嘛？再看一下Machine Learning的定义，Machine Learning (ML) is th..
初识回归分析Regression Analysis
Regression AnalysisIn statistical model, regression analysis is a set of statistical processes for estimating the relationship between a dependent variable (often called the “outcome variable”) and one or more independent variables (often called “predic..
(20210316已解决)postgresql cannot execute CREATE TABLE in a read-only transation
Overview如题，在一个postgresql 的docker container里创建数据库出现上述错误。SolutionNormally the most plausible reasons for this kinde of error are:trying create statements on a read-only replica (the entire instance is read-only)<username> has default_transact..
(20210316已解决)docker-compose创建postgresql容器exited with code 1
Overview通过docker-compose创建postgresql容器总是失败，log显示为containerName exited with code 1Exit Code 1: Indicates failure due to application errorSolutiondocker-compose.yaml文件中添加environment变量：environment: POSTGRES_USER: example POSTGRES_PASSWORD: ..
初识PostgreSQL常用命令
PostgreSQLPostgreSQL is a pwerful, open source object-relational database system with over 30 years of active development that has earned it a strong reputation for reliability, feature roubustness, and performance.Object-Relational DatabaseAn objec..
再看Exception in Python
Exceptions versus Syntax ErrorsSyntax errors occur when the parser detects an incorrect statement.Exception errors occurs whenever syntactically correct Python code results in an error.Raising an ExceptionWe can use raise to throw an exception if a..
(20210317Solved) Catch the IntegrityError about PostgreSQL in Python
Overview通过python api向postgresql存入数据出现重复数据，会报错IntegrityError，如何捕捉？Solution通过sqlalchemy使用Python API。The sqlalchemy wraps the psycopg2 exception to its own exception.from sqlalchemy.exc import IntegrityErrortry: ...except IntegrityError as e: ..
理解History of Standard SQL
SQLStructured Query Language is a domain-specific language used in programming and designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS).Hist..
初探The History of Database
Overview越来越多的用到数据库，各种数据库各种类型，感觉有必要了解一下数据库的发展历史，特别是每一种数据库之所以出现的那个当时已有数据库解决不了的痛点是什么？DatabaseA database is an organized collection of data, generally stored and accessed electronically from a computer system.The database management system (DBMS) is th..
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