Students will be able to...

• Make request to an external api to grab information

• Everything on the internet revolves around data. How do we grab it? Where can we get it? What can we do with it?

• Everything that we've done so far has been about creating and manipulating our own database
• Now we're going to start getting data from somewhere else using APIs
• API stands for Application Programming Interface
• Almost everything is an API
• For the purposes of this course, and industry talk, people are usually talking about a HTTP API.
• You can think of these as a database somebody else put together that you can pull information from.

Five Min Exercise

• Do some research on the following
  • REST
  • RESTful API
  • HTTP VERBS / CRUD

• REST stands for Representational State Transfer
• This is NOT an actually programming keyword. It is a term to describe "best practices" when creating HTTP APIs
• The four most common actions when dealing with an API are the CRUD actions

• There are eight HTTP verbs in total but the others are uncommon.
• Much of what we want to do with an api can be completed using the CRUD HTTP Verbs
• Here are all eight in case you were wondering

GET
POST
PUT
DELETE
OPTIONS
HEAD
TRACE
CONNECT

• So we did CRUD in SQL, and now we have CRUD commands with HTTP Verbs, but where do these verbs go?
• These verbs go into your HTTP Requests
• HTTP works as a request/response protocol. Your browser will make requests to a server, and that server will serve a response
• Python cannot handle requests out of the box so let's install this onto our computers

pip3 install requests

• Now we have the requests library
• remember pip3 is our package manager for Python3
• Let's see a list of all our python 3 modules

pip3 freeze

• A former student of mine built an api for D&D spells called spell-buddy
• Let's use this api along with the request library to return some values to us.

import requests

print(requests.get("http://spell-buddy.herokuapp.com/api/spells?name=magic%20missile").json())

• Maybe put this command inside a method and print the method instead?
• without .json() will return response 200
• must use .json to get the file in the correct format

• Notice in the last example we used the method .json()
• There are two types of file formats normally supported by API's. They are JSON and XML
• For the purpose of this class, and more recent up to date technologies we will be using JSON
• JSON looks like a dictionary

NOTE

• XML is used more in line with big banks or larger coorporations with older technologies.

• Endpoints are a webservice that points us to specific part of an API
• Many API's will have multiple endpoints and you have to target the right one to grab the data you want

• Google API - http://www.nycdessertmap.com/
• Weather underground API - http://jeffweather.herokuapp.com/

• Tutorial Point for HTTP Request
• Andrew Havens Beginners Guide to Creating a REST API
• Miguel Grinberg Design a RESTful API with Python and Flask
• User stories
• Pseudocode