Python - Dictionary Methods Part 2: Adding and Updating Data

These methods allow adding new entries or modifying existing key-value pairs.

Methods and Examples

update() Method Updates the dictionary with another dictionary or key-value pairs.

my_dict.update({"country": "USA", "age": 26})

print(my_dict)  # Output: {'name': 'Alice', 'age': 26, 'city': 'New York', 'country': 'USA'}

Explanation: The update() method modifies existing keys or adds new ones.

Direct Assignment Add or update a specific key-value pair.

my_dict["profession"] = "Engineer"

print(my_dict)  # Output: {'name': 'Alice', 'age': 26, 'city': 'New York', 'country': 'USA', 'profession': 'Engineer'}

Explanation: Direct assignment is simple for individual key-value additions.

Setting Default with setdefault() Sets a default value if the key does not exist.

my_dict.setdefault("hobby", "Reading")

print(my_dict)  # Output: {'name': 'Alice', 'age': 26, 'city': 'New York', 'country': 'USA', 'profession': 'Engineer', 'hobby': 'Reading'}

Explanation: setdefault() avoids overwriting existing keys while ensuring a default value.