1. Python – May 20 Reading data from the Web
Example: web.py
Practice with large amount of I/O
See lab sheet

2. Web input
Just like Java, Python has an easy way to automatically read a Web page
import urllib2
page = urllib2.urlopen(“
Can continue as if “page” is an input file
for line in page:
Example: web.py reads a stock quote.

3. Large input
Algorithm needs to be practical, in addition to correct. Beware of nested loops
Comments about the data; “density”
#3 - County population, area, density
Assume that all blocks in county are listed together.
#5 – Creating tract-level data
Need to look up tract in dictionary search for tract, because blocks in input file are not sorted by tract
Once you are finished with a county, you can output all its tracts and empty the dictionary.