On Thu, Sep 17, 2020 at 2:57 PM Brendan Barnwell <brenbarn@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