Nested f-strings

Question

Thanks to David Beazley\'s tweet, I\'ve recently found out that the new Python 3.6 f-strings can also be nested:

>>> price = 478.23
>>> f\"         


        

Answer 1

I guess this is to pass formatting parameters in the same line and thus simplify f-strings usage.

For example:

>>> import decimal
>>> width = 10
>>> precision = 4
>>> value = decimal.Decimal("12.34567")
>>> f"result: {value:{width}.{precision}}"
'result:      12.35'

Of course, it allows programmers to write absolutely unreadable code, but that's not the purpose :)