哈希表实现python

Question

我正在用python实现哈希表函数，我该如何修改put（）和delete（）函数，以便每当将密钥数据对添加到哈希表或从哈希表中删除时，就适当地更改变量计数。 以及如何更改 len （）函数以使其返回此计数。 我不知道修改代码.....

class HashTable:
def __init__(self):
    self.__size = 5
    self.__slots = [None] * self.__size
    self.__data = [None] * self.__size
    self.__deleted = "\0"

def hash_function(self, key, size):
    return key % size

def rehash(self, old_hash,size):
    return (old_hash + 1) % size

def get(self, key):
    start_slot = self.hash_function(key,len(self.__slots))
    position = start_slot

    while self.__slots[position] != None:
        if self.__slots[position] == key:
            return self.__data[position]
        else:
            position = self.rehash(position, len(self.__slots))
            if position == start_slot:
                return None
    return None

def put(self,key,data):
    hash_value = self.hash_function(key,len(self.__slots))
    if self.__slots[hash_value] == None or \
       self.__slots[hash_value] == self.__deleted:
        self.__slots[hash_value] = key
        self.__data[hash_value] = data
    elif self.__slots[hash_value] == key:
        self.__data[hash_value] = data
    else:
        next_slot = self.rehash(hash_value, len(self.__slots))
        while self.__slots[next_slot] != None\
              and self.__slots[next_slot] != self.__deleted \
              and self.__slots[next_slot] != key:
            next_slot = self.rehash(next_slot,len(self.__slots))
            if next_slot == hash_value:
                return
        if self.__slots[next_slot] == None or \
           self.__slots[next_slot] == self.__deleted:
            self.__slots[next_slot] = key
            self.__data[next_slot] = data
        else:
            self.__data[next_slot] = data

def delete(self, key):
    start_slot = self.hash_function(key, len(self.__slots))
    position = start_slot
    key_in_slot = self.__slots[position]

    while key_in_slot != None:
        if key_in_slot == key:
            self.__slots[position] = self.__deleted
            self.__data[position] = self.__deleted
            return None 
        else:
            position = self.rehash(position, len(self.__slots))
            key_in_slot = self.__slots[position]
            if position == start_slot:
                return None

def __delitem__(self, key):
    return self.delete(key)

def __setitem__(self,key,data):
    self.put(key,data)

def __getitem__(self,key):
    return self.get(key)

def __len__(self):
    count = 0
    for value in self.__slots:
        if value != None and value != self.__deleted:
            count += 1
    return count

def __contains__(self, key):
    return self.get(key) != None


def __repr__(self):
    str_rep = "["
    for i in range(len(self.__slots)):
        key = self.__slots[i]
        data = self.__data[i]
        info = ""
        if key == None or key == self.__deleted:
            info = ""
        else:
            if data == None:
                info = str(key) + ":None"
            else:
                info = str(key) + ":" + str(data)
        str_rep += info + ", "
    return str_rep[:-2] + "]"