"""
 hash.py

 A coding-in-class exercise to write a simple hash table.

  $ python hash.py 
  The cat says  meow

 Jim Mahoney | cs.marlboro.college | March 2022 | MIT License
"""

def hash_function(key):
    """ Given something (usually a string), return an integer """
    result = "0"
    for letter in str(key):
        result = result + str(ord(letter))
    return int(result)

class HashTable:

    def __init__(self):
        self.size = 101
        self.data = [None] * self.size

    def index(self, key):
        """ find the index i of this key """
        tries = 0
        max_tries = 5
        index_key = key
        while tries < max_tries:
            tries += 1
            i = hash_function(index_key) % self.size
            if self.data[i] == None: return i
            if self.data[i][0] == key: return i
            index_key += key
        return None
        
    def get(self, key):
        """ return corresponding value or None if not found """
        i = self.index(key)
        if self.data[i][0] == None: return None
        if self.data[i][0] == key: return self.data[i][1]

    def insert(self, key, value):
        """ put (key,value) into the hash table """
        i = self.index(key)
        if i==None: return
        self.data[i] = (key, value)

def main():
    hashtable = HashTable()           # create a hash table
    hashtable.insert("cat", "meow")   # insert some data into it
    meow = hashtable.get("cat")       # fetch some data from it
    print("The cat says ", meow)

main()