arrays - Python table classification

Question

I have different type of data for example:

4.5,3.5,U1
4.5,10.5,U2
4.5,6,U1
3.5,10.5,U2
3.5,10.5,U2
5,7,U1
7,6.5,U1

I need output:

'U1': [['4.5', '3.5'], ['4.5', '6'], ['5', '7'], ['7', '6.5']]
'U2': [['4.5', '10.5'], ['3.5', '10.5'], ['3.5', '10.5']]

So my code is:

import csv

reader = csv.reader(open('test.data', 'r'))
result = {}
for row in reader:
    uclass=row[-1]
    if result.has_key(uclass):
        result[uclass].append([row[0],row[1]])       #--->how can I change from 0 to -2 row ??
    else:
        result[uclass]=[[row[0],row[1]]]             #--->-->how can I change from 0 to -2 row ??
print repr(result)

But I need this code for any other input data, where there is many rows, not just 3!

See comment in code

Answer 1

result[uclass].append(row[:-1])

and

result[uclass] = row[:-1]  

This notation is called slicing.