hash.py

class Node:
    def __init__(self, key, value):
        self.key = key 
        self.value = value

class HashMap:
 
    def __init__(self):
        self.__size = 50
        self.__table = [[] for i in range(self.__size)] 

    def put(self, key, value):
        self[key] = value
 
    def get(self, key):
        for i in range(self.__size):
            for j in range(len(self.__table[i])):
                node = self.__table[i][j]
                if node.key == key:
                    return node.value
        raise Exception('key dont exists')

    def __setitem__(self, key, value):
        i = self.__hash(key)
        if len(self.__table[i]) > 0:
            for node in self.__table[i]:
                if node.key == key:
                    node.value = value
                    return
        self.__table[i].append(Node(key, value))

    def __hash(self, key):
        val = 4
        for char in key:
          val += ord(char)
        return val%self.__size

    def keys(self):
        return [node.key for list in self.__table for node in list if node]

    def values(self):
        return [node.value for list in self.__table for node in list if node]

    def clear(self):
        self.__table = [[] for i in range(self.__size)]