odict.py 文件源码

def __init__(self, *args, **kwds):
            '''Initialize an ordered dictionary.  Signature is the same as for
            regular dictionaries, but keyword arguments are not recommended
            because their insertion order is arbitrary.

            '''
            if len(args) > 1:
                raise TypeError('expected at most 1 arguments, got %d' % len(args))
            try:
                self.__root
            except AttributeError:
                self.__root = root = [None, None, None]     # sentinel node
                PREV = 0
                NEXT = 1
                root[PREV] = root[NEXT] = root
                self.__map = {}
            self.update(*args, **kwds)