Most useful websites for everyone

 M<ost useful websites for everyone


Comments

Post a Comment

Popular posts from this blog

SQLAlchemy library for python

Image
 SQLAlchemy library for python  Introduction: What is SQLAlchemy? SQLAlchemy is a popular SQL toolkit and Object Relational Mapper.  It is written in Python and gives full power and flexibility of SQL to an application developer.  It is open-source and cross-platform software released under MIT license.  SQLAlchemy is famous for its object-relational mapper (ORM), using which classes can be mapped to the database, thereby allowing the object model and database schema to develop in a cleanly decoupled way from the beginning. It is one type of ORM library, AKA an Object-Relational Mapping library, which provides an interface for using object-oriented programming to interact with a database. Other ORM libraries that exist across other languages include popular choices like javascript libraries Sequelize and Bookshelf. js for NodeJS applications, the ruby library ActiveRecord, which is used inside Ruby on Rails, and CakePHP for applications written on PHP, amongst m...
Read more

What Is Relational Databases

Image
What Is Relational Databases  Definitions : -   A database is a collection of data. -    A database system is a system for storing collections of data in some organized way. -    It uses a structure that allows us to identify and access data  in relation  to another piece of data in the database. -    Often, data in a relational database is organized into tables. What is a Relational Database Management System (RDBMS)? -    A relational database management system (RDBMS) is a program that allows you to create, update, and administer a relational database. -   Most relational database management systems use the SQL language to access the database. What is SQL? - SQL ( S tructured  Q uery  L anguage) is a programming language used to communicate with data stored in a relational database management system. - Every relational database system (PostgreSQL, SQLite, MySQL, etc) has its own "flavor" of SQL...
Read more

Python-Cheat-Sheet

Image
Python-Cheat-Sheet Variables We use variables to temporarily store data in the computer’s memory. price = 10 rating = 4.9 course_name = ‘Python for Beginners’ is_published = True In the above example, • price is an integer (a whole number without a decimal point) • rating is a float (a number with a decimal point) • course_name is a string (a sequence of characters) • i s_published is a boolean. Boolean values can be True or False. Comments We use comments to add notes to our code. Good comments explain the hows and whys, not what the code does. That should be reflected in the code itself. Use comments to add reminders to yourself or other developers, or also explain your assumptions and the reasons you’ve written code in a certain way. # This is a comment and it won’t get executed. # Our comments can be multiple lines. Receiving Input We can receive input from the user by calling the input() function. birth_year  =  i nt(input(‘Birth year: ‘)) The input() function always r...
Read more