Mastering Python: Annotations, Errors and Environment

The return annotation is used in functions to indicate what type of data will be returned. This annotation is created using the -> syntax:

Return annotations are helpful for both function users and writers, as they indicate if the function is returning an unexpected data type:

The division operator (/) returns a float value, but if we expect an int, the return annotation can help us identify this potential bug in our function.

Note

To create the return annotation, you need to use the -> and type (e.g., str) between closed parenthesis ) and colon :.