Hash Table Part 3

hash_table.py

    def contains(self, key):
        """Return True if the key is found in the HashTable,
        otherwise return False"""
        
        # get the slot (linked_list) the key belongs to
        # using our _get_hash_index function
        slot = self.slots[self._get_hash_index(key)]
        
        # look for key in linked list
        # if found return True, otherwise return False
        if slot.find_by_key(key) is not None:
            return True
        else:
            return False

    def get(self, key):
        """Return data found by given key in the HashTable,
        return None if key is not found"""
        
        # get the slot (linked_list) the key belongs to
        # using our _get_hash_index function
        slot = self.slots[self._get_hash_index(key)]
        
        # find key in linked list and return
        return slot.find_by_key(key)

    def set(self, key, value):
        """Add an item to the HashTable by key and value"""
        
        # get the slot (linked_list) the key belongs to
        # using our _get_hash_index function
        slot = self.slots[self._get_hash_index(key)]
        
        # if the item isn't already in the hash table,
        # increment size (delete item if it is)
        if not slot.delete_by_key(key): 
            self.size += 1
            
        # append item to end of slot (linked list)
        slot.append((key, value))
        
        # if load factor exceeds 0.66, resize
        if (self.size / len(self.slots)) > 0.66:
            self._resize()

    def delete(self, key):
        """Remove an item from the HashTable by key or raise KeyError if key
        is not found in the HashTable"""
        
        # get the slot (linked_list) the key belongs to
        # using our _get_hash_index function
        slot = self.slots[self._get_hash_index(key)]
        
        # delete item or throw key error if item was not found
        if slot.delete_by_key(key):
            self.size -= 1
        else:
            raise KeyError('Key {} not found in HashTable'.format(key))