#!/usr/bin/env python
# This is a class designed to sort things via an index or an attribute.
# Thus, you can sort lists of classes or lists of dicts or lists of tuples
# without much trouble.
class Sorter :
# Initialize self.__attribute . It will be abused later.
def __init__ (self) :
self.__attribute = None
# Notice how __compare is dependant upon self.__attribute
def __compare (self, x, y) :
return cmp(x[self.__attribute], y[self.__attribute])
# Pass the sort function the __compare function defined above.
def __call__ (self, data, attribute = None) :
if attribute == None :
data.sort()
else :
self.__attribute = attribute
data.sort(self.__compare)
# This is useful if you want to inline things.
# I don't know how much innefficiency it introduces.
# Is this just a new reference? (that would be cool.)
return data
# Instanciate the Sorter class once in the module.
# All calls will subsequently abuse this instance.
sort = Sorter()
if __name__ == '__main__' :
list = [(1, 2), (4, 8), (0, 3)]
dict = [{'a': 3, 'b': 4}, {'a': 5, 'b': 2}, {'a': 0, 'b': 0}, {'a': 9, 'b': 9}]
dumb = [1, 4, 6, 7, 2, 5, 9, 2, 4, 6]
print
print 'list normal:', list
sort(list, 0)
print 'sort by [0]:', list
sort(list, 1)
print 'sort by [1]:', list
print
print
print "dict normal:", dict
sort(dict, 'a')
print "sort by 'a':", dict
sort(dict, 'b')
print "sort by 'b':", dict
print
print
print 'dumb normal:', dumb
sort(dumb)
print 'normal sort:', dumb
print
