Python f-string formatting not working with strftime inline

Question

I'm hitting an odd error that I'm trying to understand. Doing some general code cleanup and converting all string formatting to f-strings. This is on Python 3.6.6

This code does not work:

from datetime import date
print(f'Updated {date.today().strftime('%m/%d/%Y')}')

  File "<stdin>", line 1
    print(f'Updated {date.today().strftime('%m/%d/%Y')}')
                                               ^
SyntaxError: invalid syntax

However, this (functionally the same) does work:

from datetime import date
d = date.today().strftime('%m/%d/%Y')
print(f'Updated {d}')

Updated 11/12/2018

I feel like I'm probably missing something obvious, and am fine with the second iteration, but I want to understand what's happening here.

Answer 1

There's a native way:

print(f'Updated {date.today():%m/%d/%Y}')

More on that:

• PEP 3101 -- Advanced String Formatting -- Controlling Formatting on a Per-Type Basis
• datetime.date.__format__