Dictionary Key-Value Operations: Tips for Adding, Removing, Modifying, and Querying in Python Dictionaries

Python dictionaries are a practical data structure for storing key-value pairs, where keys are immutable and unique types (such as strings, numbers), and values can be of any type. **Add/Modify**: Use `dict[key] = value` for assignment. If the key does not exist, it is added; if it exists, it is modified. **Delete**: `del` removes a specified key; `pop()` deletes and returns the value; `popitem()` (3.7+) deletes the last key-value pair; `clear()` empties the dictionary. **Retrieve**: Prefer `get(key, default)` for safe retrieval (to prevent KeyError); direct key access may cause errors; `keys()`, `values()`, and `items()` can be used to batch retrieve keys, values, and key-value pairs respectively. **Note**: Keys must be immutable and unique (lists cannot be used as keys). Use `get()` for retrieval, and assignment is used for both adding and modifying.