f-strings Containing Python Code

Overview

We aren’t restricted to interpolating the values of simple string variables into an f-string template. Any primitives, such as integers or floats, can be formatted. More interestingly, complex objects, including lists, tuples, dictionaries, and arbitrary objects, can be used, and we can access indexes and variables or call functions on those objects from within the format string.

Example

For example, if our email message had grouped the From and To email addresses into a tuple and placed the subject and message in a dictionary, for some reason (perhaps because that’s the input required for an existing send_mail function we want to use), we can format it like this: