Re: http://erehweb.wordpress.com/2011/02/19/no-shut-up-what-statistical-programming-languages-can-learn-from-dropbox/

Simple Python pivot table.py

"""
A simpler pivot table for non-python people.

Pythonisms present:

1. You can iterate over a list of tuples using `for ... in` and map each tuple to a variable.
2. Dicts exist and are great.
3. Iterating over a dict returns the key.
4. Attempting to access a variable that doesn't exist in a dict raises a KeyError.

While these are all language-specific things, I argue that all
can be inferred from reading the code. There are a million ways to write any given routine.
"""

# Sales is a list of tuples
sales = [('Scotland', 'Edinburgh', 20000),
      ('Scotland', 'Glasgow', 12500),
      ('Wales', 'Cardiff', 29700),
      ('Wales', 'Bangor', 12800),
      ('England', 'London', 90000),
      ('England', 'Manchester', 45600),
      ('England', 'Liverpool', 29700)]

# Use a dict to store output
out_sales = {}

# Populate output dict
for region, city, total in sales:
    # Set-or-increment that key
    try:
        out_sales[region] += total
    except KeyError:
        out_sales[region] = total

# Print the summary
for region in out_sales:
    print "%s: %d" % (region, out_sales[region])