PEP 498 – Literal String Interpolation
https://peps.python.org/pep-0498/
f-string（フォーマット済み文字列リテラル）の提案
This PEP proposed to add a new string formatting mechanism: Literal String Interpolation. In this PEP, such strings will be referred to as “f-strings”, (Abstract)
Python supports multiple ways to format text strings. These include %-formatting, str.format(), and string.Template
いずれも利点・欠点がある
printf 形式の文字列書式化
str.format 書式指定文字列の文法