In college I would've charged $5 for these, consider yourself lucky.

Python Webservices:
Class #1

Instructor: Jeff Hammel
Date: 16-9-2010

This first class took place in #p2pu-webcraft/beginning-python-webservices on irc.freenode.net since we had audio issues (static, etc) on skype.

Class started about 11:45p EDT/10:45p CDT/8:45p PDT/3:45a GMT.

Hobs was nice enough to point out the unabridged chat can be found here http://fasdf.net/channel.log

So skip past us shooting the breeze, some mentions of World of Warcraft, and some other geek stuff and we move onto the topic of webservices. I have distilled the chat into some points for everyone, please continue reading.

• Beginning python webservices will focus on learning three primary things
  • http
  • python
  • mashing them together to make webservices
• A webservice listens to HTTP requests and gives back a response
  • Can also do a number of other things that will be covered later
• Webservices that are consumable are more interesting
  • Consumable means they can be used  by multiple parties (humans and computers)
• Google’s GeoLocation webservice was looked at
  • http://code.google.com/apis/maps/documentation/geocoding/
  • This webservice takes a request using the following format:
  • http://maps.google.com/maps/api/geocode/output?parameters
  • “output” can either be json or xml (literals)
  • “parameters” is defined on the site, “address” or “latlng” is required as is “sensor”
  • Address is going to give you the latitude longitude of the address while latlng will give you the closest human readable address
    • Example:
      • http://maps.google.com/maps/api/geocode/json?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&sensor=false
      • This tells the API you want a latitude longitude for the Google Campus in Mountain View in JSON (versus XML) format. Sensor=false is telling the API you are not making this request from a device with a GPS sensor.
  • You can see example outputs here http://code.google.com/apis/maps/documentation/geocoding/#GeocodingResponses
  • Trying this in your browser will result in an access denied message because you need an API key to use the service
• Webservices are very good at solving problems that have a very finite scope
• HTTP has “verbs” we discussed two of them:
  • GET is used to request data
    • When you type www.google.com into your browser, it performs a GET request
  • POST is used to update data
    • If you’ve ever filled out a form on a webpage and clicked submit, the submit button makes the form POST its data to the server
• It’s best to compartmentalize your services
  • This means don’t make 10 webservices for your site and lump all the code into one spot, make “modules” they are far easier to debug and maintain
• There will some homework involved in the class
• Beginning Python Webservices will flip to more empirical (learn by doing) after the third class
• Next class will cover HTTP and the class after that will focus on Python, especially as it relates to the web
• Some of us decided to pronounce Webob as we-bob instead of the proper Web-Oh Bee just for kicks

 If anyone has additions, just post updates. Happy coding!