The Joy of Typing

Python's dynamic typing can be a liability in data science, leading to runtime errors that are difficult to debug in long pipelines. Modern type annotations offer a solution by allowing developers to specify intended data types, which are verified by separate static type checkers before execution. Key features include TypedDict for defining the structure of dictionary-like data, Literal for constraining values to a specific set of options, and TypeAlias for improving the readability of complex type definitions. The article also explains how to use union types, particularly the `|` syntax, to handle variables that can hold multiple types, such as a value or None.