It's a Python f-string [0]. A way of formatting a string by directly including a Python expression between curly braces. [0] https://docs.python.org/3/tutorial

It's a Python f-string [0]. A way of formatting a string by directly including a Python expression between curly braces. [0] https://docs.python.org/3/tutorial/inputoutput.html#tut-f-strings https://docs.python.org/3/tutorial/inputoutput.html#tut-f-st...