source: trunk/yaml/ordered_dict.py @ 71

# This is extremely crude implementation of an OrderedDict.
# If you know of a better implementation, please send it to
# the author Steve Howell.  You can find my email via 
# the YAML mailing list or wiki.

class OrderedDict(dict): 
    def __init__(self): 
        self._keys = [] 
 
    def __setitem__(self, key, val): 
        self._keys.append(key) 
        dict.__setitem__(self, key, val) 
 
    def keys(self): 
        return self._keys 
 
    def items(self):
        return [(key, self[key]) for key in self._keys]
 
if __name__ == '__main__': 
    data = OrderedDict()
    data['z'] = 26
    data['m'] = 13
    data['a'] = 1
    for key in data.keys(): 
        print "The value for %s is %s" % (key, data[key]) 
    print data