Merge pull request #1 from CoderDojoSF/v1

Added initial version

Author: KartikTalwar

README.md

@@ -3,15 +3,175 @@
 
 ### Introduction to REST API parsing with python!
 
+API stands for Application Programming Interface and are essentially a way to access a piece of information from a website or service. REST stands for representational state transfer which is a way of describing how APIs should look and work. In most cases, especially for web APIs, a REST interface is generally a URL that you can click to get some information from the website.
+
+We'll be using Python to make use of some web APIs! Lets get started!
 
-## Introduction
 
 ## Prerequisites
 
-## What is REST
+In order to get started, we need Python version 2.7 or higher and access to the internet. We also need some basic knowledge of python: things like defining a function and how lists and strings work
+
+## Introduction
+
+We will be using a website called firebase to get data for some of our APIs. This website has a collection of some public datasets: like weather and bus routes. We will also be using the google maps images api
+
+## JSON
+
+### Understanding JSON
+
+JSON is a format for representing data. It is a very common thing that a lot of APIs use. JSON essentially looks like this. Everything is inside `{}` and you have multiple entires which contan keys and values
+
+```json
+{
+  "key_name" : "value",
+  "numeric_key" : 42,
+  "list_items" : [1, 2, "three", "four"],
+  "dictionary" : { "another_key" : "another value" }
+}
+```
+
+### Reading JSON
+
+We are going to use these simple tricks
+
+- If it is a **number**, its a **number**!
+- If it is inside **double quotes**, it is a **string**
+- If it has **square brackets**, it is a **list**!
+- If it has **curly braces**, it is a **dictionary**
 
 ## Reading the Weather
 
+### Opening the website in python
+
+```py
+import json
+import urllib2
+
+# This is the API URL
+api = "https://publicdata-weather.firebaseio.com/sanfrancisco/currently.json"
+
+get = urllib2.urlopen(api).read()
+
+print get
+```
+
+**This gives us something like:**
+
+![](https://camo.githubusercontent.com/92500dcee84fac0a563104ed2ee62df2ae9e099b/687474703a2f2f692e696d6775722e636f6d2f4a5553354945622e706e67)
+
+### Parsing JSON in python
+
+```py
+import json
+import urllib2
+
+api = "https://publicdata-weather.firebaseio.com/sanfrancisco/currently.json"
+get = urllib2.urlopen(api).read()
+data = json.loads(get)
+
+print data
+```
+
+**This gives us something like:**
+
+![](https://cloud.githubusercontent.com/assets/461702/2912224/74e236a2-d673-11e3-866f-63355c0c44b9.JPG)
+
+
+
+
+### Writing a function to return our data
+
+```py
+import json
+import urllib2
+
+def get_data(api):
+  get = urllib2.urlopen(api).read()
+  data = json.loads(get)
+
+  return data
+  
+api = "https://publicdata-weather.firebaseio.com/sanfrancisco/currently.json"
+data = get_data(api)
+
+print data
+```
+
+### Reading JSON in Python
+
+Reading is simple. We just need to define the key name and we get back it's value!
+
+```py
+print data['temperature'] #=> 52.46
+prnt data['summary'] #=> "Partly Cloudy"
+```
+
+#### Tasks
+
+- **Lets print a few more properties**
+- **Print the temperature in Celsius**
+  - Use the formula:  `(temperature -32) * 5.0/9.0`
+
 ## Checking MUNI Status
 
+We are going to make things a little bit more interesting. We are going to find where our favorite muni bus is in the city. To do this, we are going to need just 1 thing:
+
+- The `id` of a bus
+
+
+Let's use firebase's MUNI API again
+
+
+```py
+api = "https://publicdata-transit.firebaseio.com/sf-muni/data.json"
+data = get_data(api)
+```
+
+#### DONT PRINT THIS `data` VARIABLE
+
+![](https://cloud.githubusercontent.com/assets/461702/2923448/f37b0d6a-d716-11e3-81c1-9394e7f2f5ea.JPG)
+
+## Let's find our favorite bus
+
+```py
+api = "https://publicdata-transit.firebaseio.com/sf-muni/data.json"
+data = get_data(api)
+
+def find_bus(bus_name, data):
+  for bus_id, bus_info in data.iteritems():
+    if bus_info['routeTag']:
+      return bus_info
+
+# for routes that are just numbers the input parameter 
+# should be int instead of string
+number = 'N'
+location = find_bus(number, data)
+
+latitude = location['lat']
+longitude = location['lon']
+
+print latitude
+print longitude
+```
+
+![](https://cloud.githubusercontent.com/assets/461702/2923497/8c988058-d718-11e3-88bb-8e0c1e2bcd6b.JPG)
+
 ## Lets add Maps!
+
+```py
+def get_map(latitude, longitude):
+  size = '600x450'
+  zoom = '16'
+  url = "http://maps.google.com/maps/api/staticmap?size=%s&maptype=roadmap&markers=size:mid|color:red|%s,%s&sensor=false&zoom=%s"
+  
+  return url % (size, latitude, longitude, zoom)
+
+print get_map(latitude, longitude)
+```
+
+![](http://maps.google.com/maps/api/staticmap?size=600x450&maptype=roadmap&markers=size:mid|color:red|37.7794,-122.40215&sensor=false&zoom=16)
+
+## Homework
+
+- Add more than 1 location on the map