On Thu, Sep 17, 2020 at 2:57 PM Brendan Barnwell <brenb...@brenbarn.net>
wrote:
> On 2020-09-16 21:52, Dennis Sweeney wrote:
> > TL;DR: I propose the following behavior:
> >
> > >>> s = "She turned me into a newt."
> > >>> f"She turned me into a {animal}." = s
> > >>> animal
> > 'newt'
> >
> > >>> f"A {animal}?" = s
> > Traceback (most recent call last):
> > File "<pyshell#2>", line 1, in <module>
> > f"A {animal}?" = s
> > ValueError: f-string assignment target does not match 'She turned
> me into a newt.'
> >
> > >>> f"{hh:d}:{mm:d}:{ss:d}" = "11:59:59"
> > >>> hh, mm, ss
> > (11, 59, 59)
>
A difficulty I have with the idea as presented is this.
If I can say this:
"{x:d} {y:d} {z:d}" = "1 2 3"
...thus assigning 1, 2, 3 to x, y, z respectively, I might want to also do
the same thing this way:
q = "{x:d} {y:d} {z:d}"
q = "1 2 3"
The intent being: save the f-string as a variable, and then use it to
assign later. But that can obviously never work because q would just become
the string "1 2 3" .
We can already do the reverse of this operation, of course:
>>> q = "{x:d} {y:d} {z:d}"
>>> d = dict(x=1, y=2, z=3)
>>> q = "{x:d} {y:d} {z:d}"
>>> q.format(**d)
'1 2 3'
What would be the operation we are inverting, here?
Perhaps a better way would be-- rather than assigning the values to the
global x,y,z-- create a string method that returns a dictionary with the
names and the values inside:
>>> q = "{x:d} {y:d} {z:d}"
>>> p = "1 2 3"
>>> q.parse(p)
{'x': 1, 'y': 2, 'z': 3}
..but of course this way we can to the same thing with the literal
f-string, similar to what others have proposed:
>>> "{x:d} {y:d} {z:d}".parse("1 2 3")
{'x': 1, 'y': 2, 'z': 3}
---
Ricky.
"I've never met a Kentucky man who wasn't either thinking about going home
or actually going home." - Happy Chandler
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