Hash table

A hash table is a form of list where elements are accessed by a keyword rather than an index number. At least, this is how the client code will see it. Internally, it will use a slightly modified version of our hashing function in order to find the index position in which the element should be inserted. This gives us fast lookups, since we are using an index number which corresponds to the hash value of the key.

We start by creating a class to hold hash table items. These need to have a key and a value, since our hash table is a key-value store:

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

This gives us a very simple way to store items. Next, we start working on the hash table class itself. As usual, we start off with a constructor:

    class HashTable: 
        def __init__(self): 
            self.size = 256 
            self.slots = [None for i in range(self.size)] 
            self.count = 0 

The hash...