In this tutorial, you'll learn how to store and retrieve data using Python, SQLite, and SQLAlchemy as well as with flat files. Using SQLite with Python brings with it the additional benefit of accessing data with SQL.
All programs process data in one form or another, and many need to be able to save and retrieve that data from one invocation to the next. Python, SQLite, and SQLAlchemy give your programs database functionality, allowing you to store data in a single file without the need for a database server.
You can achieve similar results using flat files in any number of formats, including CSV, JSON, XML, and even custom formats. Flat files are often human-readable text files—though they can also be binary data—with a structure that can be parsed by a computer program. Below, you’ll explore using SQL databases and flat files for data storage and manipulation and learn how to decide which approach is right for your program.
In this tutorial, you’ll learn how to use:
You can get all of the code and data you’ll see in this tutorial by clicking on the link below:
Download the sample code: Click here to get the code you'll use to learn about data management with SQLite and SQLAlchemy in this tutorial.
A flat file is a file containing data with no internal hierarchy and usually no references to external files. Flat files contain human-readable characters and are very useful for creating and reading data. Because they don’t have to use fixed field widths, flat files often use other structures to make it possible for a program to parse text.
For example, comma-separated value (CSV) files are lines of plain text in which the comma character separates the data elements. Each line of text represents a row of data, and each comma-separated value is a field within that row. The comma character delimiter indicates the boundary between data values.
Python excels at reading from and saving to files. Being able to read data files with Python allows you to restore an application to a useful state when you rerun it at a later time. Being able to save data in a file allows you to share information from the program between users and sites where the application runs.
Before a program can read a data file, it has to be able to understand the data. Usually, this means the data file needs to have some structure that the application can use to read and parse the text in the file.
Below is a CSV file named
author_book_publisher.csv, used by the first example program in this tutorial:
first_name,last_name,title,publisher Isaac,Asimov,Foundation,Random House Pearl,Buck,The Good Earth,Random House Pearl,Buck,The Good Earth,Simon & Schuster Tom,Clancy,The Hunt For Red October,Berkley Tom,Clancy,Patriot Games,Simon & Schuster Stephen,King,It,Random House Stephen,King,It,Penguin Random House Stephen,King,Dead Zone,Random House Stephen,King,The Shining,Penguin Random House John,Le Carre,"Tinker, Tailor, Solider, Spy: A George Smiley Novel",Berkley Alex,Michaelides,The Silent Patient,Simon & Schuster Carol,Shaben,Into The Abyss,Simon & Schuster
The first line provides a comma-separated list of fields, which are the column names for the data that follows in the remaining lines. The rest of the lines contain the data, with each line representing a single record.
Note: Though the authors, books, and publishers are all real, the relationships between books and publishers are fictional and were created for the purposes of this tutorial.
Next, you’ll take a look at some of the advantages and disadvantages of using flat files like the above CSV to work with your data.
In this tutorial, you’re going to learn a variety of Python tricks that you can use to write your Python code in a more readable and efficient way like a pro.
Today you're going to learn how to use Python programming in a way that can ultimately save a lot of space on your drive by removing all the duplicates. We gonna use Python OS remove( ) method to remove the duplicates on our drive. Well, that's simple you just call remove ( ) with a parameter of the name of the file you wanna remove done.
In the programming world, Data types play an important role. Each Variable is stored in different data types and responsible for various functions. Python had two different objects, and They are mutable and immutable objects.
Magic Methods are the special methods which gives us the ability to access built in syntactical features such as ‘<’, ‘>’, ‘==’, ‘+’ etc.. You must have worked with such methods without knowing them to be as magic methods. Magic methods can be identified with their names which start with __ and ends with __ like __init__, __call__, __str__ etc. These methods are also called Dunder Methods, because of their name starting and ending with Double Underscore (Dunder).
The OS module is a python module that provides the interface for interacting with the underlying operating system that Python is running.