Declare a variable with a union type allowing multiple possible types (bool, str, int) and initialize it via a function call.

Indicate that the variable may hold one of several types, enabling flexible handling of input that could be boolean, string, or integer.

When a function `get_value()` may return different types based on input (e.g., parsing user input, reading config, processing API responses).

Variable assignment with type annotations, dynamic typing scenarios, configuration parsing, input validation, API response handling.

variable: Union[type1, type2, type3] = function_call()

variable: Union[type1, type2, type3] = function_call()

variable_name, Union[type1, type2, type3], function_call()

• value
• Union
• bool
• str
• int
• get_value

• float
• list
• dict

Forgetting to import Union from typing; using the | union syntax in Python <3.10; forgetting to handle all possible types in downstream code.

value: bool = get_value(); value: str = get_value(); value: int = get_value()

Confusing Union with Optional (which is Union[T, None]); assuming the variable can hold multiple types simultaneously.

• type annotation
• variable assignment
• union type

Indicates the variable can hold exactly one of the listed types at runtime, enabling polymorphic handling without losing type safety.

Signals that the variable's type is flexible, allowing code to accept boolean, string, or integer inputs while maintaining static type checking.

value: Union[bool, str, int] = get_value()

value: Union[bool, str, int, float] = get_value() # or use TypedDict/dataclass for richer structure