Nov 17 sec 01

lst = [("a", 6, "mo"), ("z", 2, "flo"), ("v", 9, "bo"), ("g", 7, "joe")]
import operator
y = sorted(lst)
print y
[('a', 6, 'mo'), ('g', 7, 'joe'), ('v', 9, 'bo'), ('z', 2, 'flo')]

y = sorted(lst, key=operator.itemgetter(2))
print y
[('v', 9, 'bo'), ('z', 2, 'flo'), ('g', 7, 'joe'), ('a', 6, 'mo')]

lst.append(('a', 7, "bo"))

print lst
[('a', 6, 'mo'), ('z', 2, 'flo'), ('v', 9, 'bo'), ('g', 7, 'joe'), ('a', 7, 'bo')]




z = sorted(lst, key=operator.itemgetter(1),reverse=True)
print z
[('v', 9, 'bo'), ('g', 7, 'joe'), ('a', 7, 'bo'), ('a', 6, 'mo'), ('z', 2, 'flo')]


# This next line sorts list z that was sorted above on the second items
# (those in slot 1) in the tuple. This time it sorts it on the first item
# in the tuples. Note that for 'a' which has two tuples, the items 7 and 6 
# are still in the order that resulted from the first sort. 

z = sorted(z, key=operator.itemgetter(0))
print z
[('a', 7, 'bo'), ('a', 6, 'mo'), ('g', 7, 'joe'), ('v', 9, 'bo'), ('z', 2, 'flo')]


# Here we sort the original list lst on the first item in the tuples. With the 
# two a's, note that the second item in each tuple, the 6 and 7 are in the same # order they were in the original list. 
z = sorted(lst, key=operator.itemgetter(0))
print z
[('a', 6, 'mo'), ('a', 7, 'bo'), ('g', 7, 'joe'), ('v', 9, 'bo'), ('z', 2, 'flo')]