Learning Flask Framework: Build dynamic, data-driven websites and modern web applications with Flask

€36.99

4.5 (2 Ratings)

Paperback Nov 2015 250 pages 1st Edition

€36.99

Paperback Nov 2015 250 pages 1st Edition

What do you get with Print?

Instant access to your digital eBook copy whilst your Print order is Shipped

Paperback book shipped to your preferred address

Download this book in EPUB and PDF formats

Access this title in our online reader with advanced features

DRM FREE - Read whenever, wherever and however you want

View table of contents

Preview Book

Learning Flask Framework

Chapter 2. Relational Databases with SQLAlchemy

Relational databases are the bedrock upon which almost every modern Web application is built. Learning to think about your application in terms of tables and relationships is one of the keys to a clean, well-designed project. As you will see in this chapter, the data model you choose early on will affect almost every facet of the code that follows. We will be using SQLAlchemy, a powerful object relational mapper that allows us to abstract away the complexities of multiple database engines, to work with the database directly from within Python.

In this chapter, we shall:

Present a brief overview of the benefits of using a relational database
Introduce SQLAlchemy, the Python SQL Toolkit and Object Relational Mapper
Configure our Flask application to use SQLAlchemy
Write a model class to represent blog entries
Learn how to save and retrieve blog entries from the database
Perform queries – sorting, filtering, and aggregation
Build a tagging...

Building a tagging system

Tags are a lightweight taxonomy system that is perfect for blogs. Tags allow you to apply multiple categories to a blog post and allow multiple posts to be related to one another outside their category. On my own blog I use tags to organize the posts, so that people interested in reading my posts about Flask need only look under the "Flask" tag and find all the relevant posts. As per the spec that we discussed in Chapter 1, Creating Your First Flask Application, each blog entry can have as few or as many tags as you want, so a post about Flask might be tagged with both Flask and Python. Similarly, each tag (for example, Python) can have multiple entries associated with it. In database parlance, this is called a many-to-many relationship.

In order to model this, we must first create a model to store tags. This model will store the names of tags we use, so after we've added a few tags the table might look something like the following one:

id	tag
1...

Description

Flask is a small and powerful web development framework for Python. It does not presume or force a developer to use a particular tool or library. Flask supports extensions that can add application features as if they were implemented in Flask itself. Flask’s main task is to build web applications quickly and with less code. With its lightweight and efficient web development framework, Flask combines rapid development and clean, simple design. This book will take you through the basics of learning how to apply your knowledge of Python to the web. Starting with the creation of a “Hello world” Flask app, you will be introduced to the most common Flask APIs and Flask’s interactive debugger. You will learn how to store and retrieve blog posts from a relational database using an ORM and also to map URLs to views. Furthermore, you will walk through template blocks, inheritance, file uploads, and static assets. You will learn to authenticate users, build log in/log out functionality, and add an administrative dashboard for the blog. Moving on, you will discover how to make Ajax requests from the template and see how the Mock library can simplify testing complex interactions. Finally, you will learn to deploy Flask applications securely and in an automated, repeatable manner, and explore some of the most popular Flask resources on the web.

Who is this book for?

This book is for anyone who wants to develop their knowledge of Python into something that can be used on the web. Flask follows the Python design principles and can be easily understood by anyone who knows Python, and even by those who do not.

What you will learn

Create your web pages to add modularity and flexibility to your web app using templates
Store and retrieve relational data using SQLAlchemy
Develop schema migrations with Alembic
Produce an admin section using flaskadmin
Build RESTful APIs using FlaskRestless
Simulate requests and sessions using the Flask test client
Make Ajax requests from Jinja2 templates

Estimated delivery fee Deliver to Greece

Premium delivery 7 - 10 business days

€17.95

(Includes tracking information)

What do you get with Print?

Instant access to your digital eBook copy whilst your Print order is Shipped

Paperback book shipped to your preferred address

Download this book in EPUB and PDF formats

Access this title in our online reader with advanced features

DRM FREE - Read whenever, wherever and however you want

Frequently bought together

Learning Flask Framework

Nov 2015 250 pages

4.5 (2)

eBook

€8.99 ~~€29.99~~

Flask Blueprints

Nov 2015 198 pages

3.3 (3)

eBook

€8.99 ~~€29.99~~

Mastering Flask

Sep 2015 288 pages

3.6 (25)

eBook

€8.99 ~~€29.99~~

Total € 110.97

€36.99

Total € 110.97

FAQs

What is the delivery time and cost of print book?

Shipping Details

USA:

Economy: Delivery to most addresses in the US within 10-15 business days

Premium: Trackable Delivery to most addresses in the US within 3-8 business days

UK:

Economy: Delivery to most addresses in the U.K. within 7-9 business days.
Shipments are not trackable

Premium: Trackable delivery to most addresses in the U.K. within 3-4 business days!
Add one extra business day for deliveries to Northern Ireland and Scottish Highlands and islands

EU:

Premium: Trackable delivery to most EU destinations within 4-9 business days.

Australia:

Economy: Can deliver to P. O. Boxes and private residences.
Trackable service with delivery to addresses in Australia only.
Delivery time ranges from 7-9 business days for VIC and 8-10 business days for Interstate metro
Delivery time is up to 15 business days for remote areas of WA, NT & QLD.

Premium: Delivery to addresses in Australia only
Trackable delivery to most P. O. Boxes and private residences in Australia within 4-5 days based on the distance to a destination following dispatch.

India:

Premium: Delivery to most Indian addresses within 5-6 business days

Rest of the World:

Premium: Countries in the American continent: Trackable delivery to most countries within 4-7 business days

Asia:

Premium: Delivery to most Asian addresses within 5-9 business days

Disclaimer:
All orders received before 5 PM U.K time would start printing from the next business day. So the estimated delivery times start from the next day as well. Orders received after 5 PM U.K time (in our internal systems) on a business day or anytime on the weekend will begin printing the second to next business day. For example, an order placed at 11 AM today will begin printing tomorrow, whereas an order placed at 9 PM tonight will begin printing the day after tomorrow.

Unfortunately, due to several restrictions, we are unable to ship to the following countries:

Afghanistan
American Samoa
Belarus
Brunei Darussalam
Central African Republic
The Democratic Republic of Congo
Eritrea
Guinea-bissau
Iran
Lebanon
Libiya Arab Jamahriya
Somalia
Sudan
Russian Federation
Syrian Arab Republic
Ukraine
Venezuela

What is custom duty/charge?

Customs duty are charges levied on goods when they cross international borders. It is a tax that is imposed on imported goods. These duties are charged by special authorities and bodies created by local governments and are meant to protect local industries, economies, and businesses.

Do I have to pay customs charges for the print book order?

The orders shipped to the countries that are listed under EU27 will not bear custom charges. They are paid by Packt as part of the order.

List of EU27 countries: www.gov.uk/eu-eea:

A custom duty or localized taxes may be applicable on the shipment and would be charged by the recipient country outside of the EU27 which should be paid by the customer and these duties are not included in the shipping charges been charged on the order.

How do I know my custom duty charges?

The amount of duty payable varies greatly depending on the imported goods, the country of origin and several other factors like the total invoice amount or dimensions like weight, and other such criteria applicable in your country.

For example:

If you live in Mexico, and the declared value of your ordered items is over $ 50, for you to receive a package, you will have to pay additional import tax of 19% which will be $ 9.50 to the courier service.
Whereas if you live in Turkey, and the declared value of your ordered items is over € 22, for you to receive a package, you will have to pay additional import tax of 18% which will be € 3.96 to the courier service.

How can I cancel my order?

Cancellation Policy for Published Printed Books:

You can cancel any order within 1 hour of placing the order. Simply contact customercare@packt.com with your order details or payment transaction id. If your order has already started the shipment process, we will do our best to stop it. However, if it is already on the way to you then when you receive it, you can contact us at customercare@packt.com using the returns and refund process.

Please understand that Packt Publishing cannot provide refunds or cancel any order except for the cases described in our Return Policy (i.e. Packt Publishing agrees to replace your printed book because it arrives damaged or material defect in book), Packt Publishing will not accept returns.

What is your returns and refunds policy?

Return Policy:

We want you to be happy with your purchase from Packtpub.com. We will not hassle you with returning print books to us. If the print book you receive from us is incorrect, damaged, doesn't work or is unacceptably late, please contact Customer Relations Team on customercare@packt.com with the order number and issue details as explained below:

If you ordered (eBook, Video or Print Book) incorrectly or accidentally, please contact Customer Relations Team on customercare@packt.com within one hour of placing the order and we will replace/refund you the item cost.
Sadly, if your eBook or Video file is faulty or a fault occurs during the eBook or Video being made available to you, i.e. during download then you should contact Customer Relations Team within 14 days of purchase on customercare@packt.com who will be able to resolve this issue for you.
You will have a choice of replacement or refund of the problem items.(damaged, defective or incorrect)
Once Customer Care Team confirms that you will be refunded, you should receive the refund within 10 to 12 working days.
If you are only requesting a refund of one book from a multiple order, then we will refund you the appropriate single item.
Where the items were shipped under a free shipping offer, there will be no shipping costs to refund.

On the off chance your printed book arrives damaged, with book material defect, contact our Customer Relation Team on customercare@packt.com within 14 days of receipt of the book with appropriate evidence of damage and we will work with you to secure a replacement copy, if necessary. Please note that each printed book you order from us is individually made by Packt's professional book-printing partner which is on a print-on-demand basis.

What tax is charged?

Currently, no tax is charged on the purchase of any print book (subject to change based on the laws and regulations). A localized VAT fee is charged only to our European and UK customers on eBooks, Video and subscriptions that they buy. GST is charged to Indian customers for eBooks and video purchases.

What payment methods can I use?

You can pay with the following card types:

Visa Debit
Visa Credit
MasterCard
PayPal

What is the delivery time and cost of print books?

Shipping Details

USA:

Economy: Delivery to most addresses in the US within 10-15 business days

Premium: Trackable Delivery to most addresses in the US within 3-8 business days

UK:

Economy: Delivery to most addresses in the U.K. within 7-9 business days.
Shipments are not trackable

Premium: Trackable delivery to most addresses in the U.K. within 3-4 business days!
Add one extra business day for deliveries to Northern Ireland and Scottish Highlands and islands

EU:

Premium: Trackable delivery to most EU destinations within 4-9 business days.

Australia:

India:

Premium: Delivery to most Indian addresses within 5-6 business days

Rest of the World:

Premium: Countries in the American continent: Trackable delivery to most countries within 4-7 business days

Asia:

Premium: Delivery to most Asian addresses within 5-9 business days

Unfortunately, due to several restrictions, we are unable to ship to the following countries:

Afghanistan
American Samoa
Belarus
Brunei Darussalam
Central African Republic
The Democratic Republic of Congo
Eritrea
Guinea-bissau
Iran
Lebanon
Libiya Arab Jamahriya
Somalia
Sudan
Russian Federation
Syrian Arab Republic
Ukraine
Venezuela

James Anderson Jun 01, 2017

A good book to learn from, but needs to updated to the latest Flask software.

Amazon Verified review

Zweibier Jul 09, 2016

I read few books on Flask, and this is one is quite good.The book walks through, step by step, building of a moderately complex Flask application, a blog engine.Many important aspects are discussed in detail, including model persistence with SQLAlchemy, login subsystem with Flask-login, building REST API with Flask-Restless and so on.By working through this book, I have learned how to design, structure, and build a real-world Flask application with all bells and whistles.Why not 5 stars then?Editing is quite subpar, there are many mistakes which should've be easily uncovered by a diligent editor, there is no errata (at least I didn't find it), no github repository with chapter by chapter source code; all I was able to find, was a source code of the completed application, on the publisher's Web site,

Learning Flask Framework: Build dynamic, data-driven websites and modern web applications with Flask

What do you get with Print?

Learning Flask Framework

Chapter 2. Relational Databases with SQLAlchemy

Why use a relational database?

Introducing SQLAlchemy

Creating the Entry model

Note

Retrieving blog entries

Building a tagging system

Why use a relational database?

Introducing SQLAlchemy

Page 1 of 8

Description

Who is this book for?

What you will learn

Product Details

What do you get with Print?

Product Details

Frequently bought together

Table of Contents

Recommendations for you

Customer reviews

People who bought this also bought

FAQs

Learning Flask Framework: Build dynamic, data-driven websites and modern web applications with Flask

What do you get with Print?

Contact Details

Shipping Address

Billing Address

Description

Who is this book for?

What you will learn

Product Details

What do you get with Print?

Contact Details

Shipping Address

Billing Address

Product Details

Packt Subscriptions

Frequently bought together

Table of Contents

Recommendations for you

Customer reviews

People who bought this also bought

FAQs