An application programming interface (API) sounds like a fancy concept, but it is not. An API is a standardized way of sharing data on the Web. Many websites share data through API endpoints. There are too many available APIs to list in this book, but here are some you might find useful or interesting:
All of these are examples of APIs that return data. You make a request to the API, and the API returns data. APIs can also serve as a way to interact with other applications. For example, we could use the Twitter API to get data from Twitter and build another application that interacts with Twitter (e.g., an application that posts Tweets using the API). The Google API list is another example—most APIs allow you to interact with the company’s services. With the LinkedIn API, you can retrieve data, but also post updates to LinkedIn without going through the web interface. Because an API can do many different things, it should be considered a service. For our purposes, the service provides data.
In this chapter, you will request API data and save it to your computer. APIs usually return JSON, XML, or CSV files, which means after the data is saved locally to your computer, you just need to apply the skills you learned in the early chapters of this book to parse it. The API we will be working with in this chapter is the Twitter API.
We chose the Twitter API as an example for a number of reasons. ...