Dictionary Methods and Operations

View Methods

• keys() - Returns view of keys
• values() - Returns view of values
• items() - Returns view of (key, value) pairs

Modification Methods

• update(other) - Merge dictionaries
• setdefault(key, default) - Get or set default

Removal Methods

• pop(key) - Remove and return
• popitem() - Remove last pair
• clear() - Remove all

Dict Comprehension

squares = {x: x**2 for x in range(5)}
inverted = {v: k for k, v in d.items()}

Copying

• d.copy() or dict(d) - Shallow copy
• copy.deepcopy(d) - Deep copy

Merging (Python 3.9+)

combined = d1 | d2
d1 |= d2  # In-place

Key Points

• update() merges dictionaries
• setdefault() gets or sets default value
• copy() makes shallow copy
• Never use mutable default with fromkeys()