Book Image

Python Programming Blueprints

By : Daniel Furtado, Marcus Pennington
Book Image

Python Programming Blueprints

By: Daniel Furtado, Marcus Pennington

Overview of this book

Python is a very powerful, high-level, object-oriented programming language. It's known for its simplicity and huge community support. Python Programming Blueprints will help you build useful, real-world applications using Python. In this book, we will cover some of the most common tasks that Python developers face on a daily basis, including performance optimization and making web applications more secure. We will familiarize ourselves with the associated software stack and master asynchronous features in Python. We will build a weather application using command-line parsing. We will then move on to create a Spotify remote control where we'll use OAuth and the Spotify Web API. The next project will cover reactive extensions by teaching you how to cast votes on Twitter the Python way. We will also focus on web development by using the famous Django framework to create an online game store. We will then create a web-based messenger using the new Nameko microservice framework. We will cover topics like authenticating users and, storing messages in Redis. By the end of the book, you will have gained hands-on experience in coding with Python.
Table of Contents (17 chapters)
Title Page
Copyright and Credits
Dedication
Contributors
Packt Upsell
Preface
Index

Testing our application


Let's test our application. First, we are going to show the help message to see which options we have available:

Nice! Just as expected. Now, we can use the --setbasecurrency argument to set the base currency:

Here, I have set the base currency to SEK (Swedish Kronor) and, every time I need to perform a currency conversion, I don't need to specify that my base currency is SEK. Let's convert 100 SEK to USD (United States Dollars):

As you can see, we didn't have the exchange rate in the database yet, so the first thing the application does is to fetch it from fixer.io and save it into the database.

Since I am a Brazilian developer based in Sweden, I want to convert SEK to BRL (Brazil Real) so that I know how much Swedish Crowns I will have to take to Brazil next time I go to visit my parents:

Note that, since this is the second time that we are running the application, we already have exchange rates with  SEK as the base currency, so the application does not fetch the data...