my_dict.py

class MyDict(object):
    def __init__(self, size=99999):
        self.hash_list = [list() for _ in range(size)]
        self.size = size
        self.length = 0

    def __setitem__(self, key, value):
        hashed_key = hash(key) % self.size
        for item in self.hash_list[hashed_key]:
            if item[0] == key:
                item[1] = value
                break
        else:
            self.hash_list[hashed_key].append([key, value])
            self.length += 1

    def __getitem__(self, key):
        for item in self.hash_list[hash(key) % self.size]:
            if item[0] == key:
                return item[1]
        raise KeyError(key)

    def __contains__(self, key):
        for item in self.hash_list[hash(key) % self.size]:
            if item[0] == key:
                return True
        return False

    def __repr__(self):
        result = []
        for sub_list in self.hash_list:
            if not sub_list:
                continue
            for item in sub_list:
                result.append(str(item[0]) + ": " + str(item[1]))
        return "{" + ", ".join(result) + "}"

    def __iterate_kv(self):
        for sub_list in self.hash_list:
            if not sub_list:
                continue
            for item in sub_list:
                yield item

    def __iter__(self):
        for kv_pair in self.__iterate_kv():
            yield kv_pair[0]

    def keys(self):
        return self.__iter__()

    def values(self):
        for kv_pair in self.__iterate_kv():
            yield kv_pair[1]

    def items(self):
        return self.__iterate_kv()

    def __len__(self):
        return self.length