Why does python 3 have a format function for strings?

Question

Python

How is "{}".format('hello world') different from f"{number}" ?
It is more convenient for me to use f"{number}", but the thought creeps in that suddenly it is more expensive in terms of performance

Answer 1

f notation, introduced in python 3.6, earlier versions had .format . There are no functional differences, there is a difference in readability and conciseness, I use the f notation.