TypedDict

Python 3.11

Special construct to add type hints to a dictionary. At runtime it is a plain dict.

Syntax

PYTHON

class typing.TypedDict(dict)

Examples

Example 1

PYTHON

class Point2D(TypedDict):
    x: int
    y: int
    label: str

a: Point2D = {'x': 1, 'y': 2, 'label': 'good'}   OK
b: Point2D = {'z': 3, 'label': 'bad'}            Fails type check

assert Point2D(x=1, y=2, label='first') == dict(x=1, y=2, label='first')

Example 2

PYTHON

Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': str})

Example 3

PYTHON

Point2D = TypedDict('Point2D', x=int, y=int, label=str)

Example 4

PYTHON

raises SyntaxError
class Point2D(TypedDict):
    in: int   'in' is a keyword
    x-y: int   name with hyphens

 OK, functional syntax
Point2D = TypedDict('Point2D', {'in': int, 'x-y': int})

Example 5

PYTHON

class Point2D(TypedDict):
    x: int
    y: int
    label: NotRequired[str]

 Alternative syntax
Point2D = TypedDict('Point2D', {'x': int, 'y': int, 'label': NotRequired[str]})

TypedDict

Syntax

Examples

See Also