related lists mean value

[John Posner]

On 3/8/2010 9:43 PM, John Posner wrote:
> On 3/8/2010 9:39 PM, John Posner wrote:
>
> <snip>

>> obj.id = y[i] <--- statement redundant, remove it

Sorry for the thrashing! It's more correct to say that the Tally class 
doesn't require an "id" attribute at all. So the code becomes:

#---------
from collections import defaultdict

class Tally:
     def __init__(self):
         self.total = 0
         self.count = 0

x = [1 ,2, 8, 5, 0, 7]
y = ['a', 'a', 'b', 'c', 'c', 'c']

# gather data
tally_dict = defaultdict(Tally)
for i in range(len(x)):
     obj = tally_dict[y[i]]
     obj.total += x[i]
     obj.count += 1

# process data
result_list = []
for key in sorted(tally_dict):
     obj = tally_dict[key]
     mean = 1.0 * obj.total / obj.count
     result_list.extend([mean] * obj.count)
print result_list
#---------

-John