Data Extraction from APIs with Python – Currency Exchange

There are several popular platforms that give developers access to their “web services”, aka “APIs” (Application Programming Interface). So using APIs is the official way for data extraction and doing other stuff allowed by such applications. You can even benefit from some APIs to build other applications. REST APIs usually generate output in JSON or XML format because most of programming languages can handle these formats easily. In fact, JSON (JavaScript Object Notation) is very similar to data types in programming languages; for example, it is very similar to Python dictionaries. If a REST API allows you to get the data you want to retrieve, then you do not need regular web scraping.

Some APIs require authentication (API Key or Client ID and Client Secret, similar to a username and password, so to speak) to control their usage, and some do not. We will explain this later in multiple APIs. For the purpose of clarifying the basics, we will start with a very simple currency rate conversion API that does not require any authentication.

So this tutorial explains how to use Python to extract data from which is -according to its official website- “a free JSON API for current and historical foreign exchange rates published by the European Central Bank.” Continue reading “Data Extraction from APIs with Python – Currency Exchange”