Hash index equality mock concept in Python

class HashIndex:
    def __init__(self):
        self._buckets = {}

    def insert(self, key, value):
        """Insert a key-value pair into the hash index."""
        index = hash(key) % 10
        if index not in self._buckets:
            self._buckets[index] = []
        self._buckets[index].append((key, value))

    def lookup(self, key):
        """Retrieve the value associated with a key."""
        index = hash(key) % 10
        if index in self._buckets:
            for stored_key, stored_value in self._buckets[index]:
                if stored_key == key:
                    return stored_value
        return None

    def __repr__(self):
        return f"HashIndex(buckets={self._buckets})"


if __name__ == "__main__":
    index = HashIndex()
    index.insert("apple", 5)
    index.insert("banana", 8)
    index.insert("orange", 3)
    index.insert("apple", 12)  # Duplicate key, stored as separate entry

    print(index.lookup("apple"))
    print(index.lookup("banana"))
    print(index.lookup("missing"))
    print(index)