On 2/11/2022 5:33 PM, Ricky Teachey wrote:
On Fri, Feb 11, 2022 at 4:58 PM MRAB <pyt...@mrabarnett.plus.com> wrote:
On 2022-02-11 20:05, Ricky Teachey wrote:
> Just had a thought kernel: what if there were an f-string
mini-language
> directive to grab environment variables and expand user paths? That
> seems to me like it could be even more useful beyond just
working with
> paths.
>
> Maybe something like:
>
> f"{my_var:$}"
>
> This would return the same as os.path.expandvars("$my_var")
>
No, that would be the value of the Python variable 'my_var' with the
format string "$".
well right now $ is not a valid format string for f-strings.
Off topic: there are no characters that are invalid format strings,
except '!' and ':'. For example, datetime allows anything, since it's
passed on to strftime:
>>> from datetime import date
>>> f'{datetime.now():This is a test $@$&*()}'
'This is a test $@$&*()'
Or:
>>> class F:
... def __format__(self, fmt):
... if fmt == '$':
... return 'dollar'
... return 'something else'
...
>>> f'{F():$}'
'dollar'
>>> f'{F():x}'
'something else'
Eric
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