Implement a Key-Value Store | Dataford Interview Questions

Implement a key-value store in a language of your choice that supports add, delete and lookup operations.

Asked in the Round 1: coding stage. Original wording: 自选语言完成key value store，实现添加，删除，查询功能

Contract

Implement key_value_store(operations). Each operation is a list: ['add', key, value], ['delete', key], or ['lookup', key]. Return a list containing the value for each lookup, or None when the key does not exist. Adding an existing key replaces its value. Deleting a missing key has no effect.

Constraints

1 <= len(operations) <= 10^4
Each operation is valid and is one of add, delete, or lookup
Keys are strings
Values are JSON-compatible primitive values
Adding an existing key replaces its value

Function Signature

def key_value_store(operations):

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