Despite being so cool, it's also a very under utilized feature, as it inherits all the formatting capabilities of format().

With format(), and hence with f-string you can:

# Replace datetime.stftime()

>>> f"{datetime.now():%m/%d/%y}"

'05/15/19'

# Show numbers in another base

>>> f"{878:b}"

'1101101110'

>>> f"{878:x}"

'36e'

>>> f"{878:e}"

'8.780000e+02'

>>> f"{878:o}"

'1556'

# Control the display of padding, filling, and precision of numbers

>>> 1 / 3

0.3333333333333333

>>> f"{1 / 3:.2f}"

'0.33'

>>> f"{69:4d}"

' 69'

>>> f"{69:=+8d}" '+ 69'

>>> f"{69:0=8d}"

'00000069'

# Center text

>>> f"{'foo':^10}"

' foo '

And so many other things, since you can create your custom __format__.

Not affiliated, but in this regard, I quite love https://pyformat.info/ as a format cheat sheet.