Python Workshops for Beginners/Saturday October 25th lecture

Welcome to the Saturday lecture section of the Boston Python Workshop! For about 2 hours, we'll work through an introduction to the Python programming language via both a lecture and hand-on exercises.

Resources

• Python data types cheat sheet
• Python loops cheat sheet
• Full slides deck

Lecture Outline

1. Introduction to APIs
   • definition of API: just an interface for programs
   • definition of web API
     • way to ask for data (almost always a URL)
     • way to get data back (almost always in a format called JSON)
     • every API is different, and documented
   • to use APIs to build a dataset we will need:
     • all our tools from last session: variables, etc
     • the ability to open urls on the web
     • the ability to create custom URLS
     • the ability to save to files
     • the ability to understand (i.e., parse) JSON data that APIs usually give us
2. New programming concepts:
   • urllib2 and urlopen
   • interpolate variables into a string using % and %()s
   • open files and write to them
3. placekitten.com
   • API that takes specially crafted URLs and gives appropriately sized picture of kittens
   • example of placekitten in browser
     • visit the API documentation
     • kittens of different sizes
     • kittens in greyscale or color
   • show how to use place
   • write a small program to grab arbitrary square from placekitten by asking for the size on standard in
4. Other APIs
   • every API is different, so read the documentation!
   • for popular APIs, there are python modules that help you make requests and parse json!
   • rate limiting
   • authentication
   • text encoding issues