【说站】python哈希散列的映射

class Map(object):
    def __init__(self,size=11):
        self.size = size
        self.__slots = [None] * self.size
        self.__data = [None] * self.size
 
    def put(self, key, val):
        hashvalue = self.hashfunction(key, len(self.__slots))
        if self.__slots[hashvalue] == None:
            self.__slots[hashvalue] = key
            self.__data[hashvalue] = val
        else:
            if self.__slots[hashvalue] == key:
                self.__data[hashvalue] = val
            else:
                nextslot = self.rehash(hashvalue, len(self.__slots))
                while self.__slots[nextslot] != None and self.__slots[nextslot] != key:
                    nextslot = self.rehash(nextslot, len(self.__slots))
                if self.__slots[nextslot] == None:
                    self.__slots[nextslot] = key
                    self.__data[nextslot] = val
                else:
                    self.__data[nextslot] = val
 
    def get(self, key):
        startslot = self.hashfunction(key, len(self.__slots))
        data = None
        stop = False
        found = False
        position = startslot
        while self.__slots[position] != None and \
                not found and not stop:
            if self.__slots[position] == key:
                found = True
                data = self.__data[position]
            else:
                position = self.rehash(position, len(self.__slots))
            if position == startslot:
                stop = True
        return data
    def delete(self,key):
        pass
    def __getitem__(self, key):
        return self.get(key)
 
    def __setitem__(self, key, val):
        self.put(key, val)
    def __delitem__(self, key):
        self.delete(key)
 
    def len(self):
        pass
 
    def hashfunction(self, key, size):
        return key % size
 
    def rehash(self, oldhash, size):
        return (oldhash + 1) % size