It does exactly the same as the C version and is more readable. Or am I missing something?
My point is exactly that it is not easily readable compared to C version. Also, unnecessarily verbose. The order of components is rather awkward. I came to this, because people seem to want one-liners for certain things and what I came up with is that maybe more concise if-else expression could help. # Fairly reasonable case. def foo(a: bool, c: float, d: float) val = a ? (c ? c : d) : (d ? d : c) return val # Comapred to def bar(a: bool, c: float, d: float) val = (c if c else d) if a else (d if d else c) return val Maybe for someone who majored in languages python’s if-else is more easily understood. To me, personally, 2nd one is unbearable, while 1st one is fairly pleasant and satisfying. This whole thing started from dict’s `get` extension: def get_substitute(self, key, default=None, subs=()): return key in self ? (self[key] := val in subs ? subs[val] : val) : default I dare you to do a 1-liner with current if-else. Also, https://peps.python.org/pep-0505/ <https://peps.python.org/pep-0505/> Why was it even considered if it doesn’t introduce any new functionality? I also dare you go through that PEP’s examples and re-write them with current if-else expression. So maybe, just maybe, making already existing expression more readable can also be a valid suggestion? As I said, in my opinion it would solve many existing queries and requests, just because certain things would become very pleasant and obvious how to do in simple one-liners. Simpler and more logically convenient if-else combined with other elegant python expressions would potentially fill that gap. From where I currently stand it just seems fairly happy middle solution between: very concise narrow functionality requests and very verbose ways of how they need to be done at the moment. I fully appreciate how likely what I am proposing is going to be even considered. But I really think it should be.
On 17 Jul 2023, at 18:09, Rob Cliffe <rob.cliffe@btinternet.com> wrote:
On 15/07/2023 21:08, Dom Grigonis wrote:
Just to add. I haven’t thought about evaluation. Thus, to prevent evaluation of unnecessary code, introduction of C-style expression is needed anyways:
1. result = bar is None ? default : bar
The below would have to evaluate all arguments, thus not achieving benefits of PEP505.
2. result = ifelse(bar is None, default, bar)
So I would vote for something similar to:
result = bar is None ? default : bar
Where default and bar is only evaluated if needed. Although not to the extent as initially intended, it would offer satisfiable solutions to several proposals.
Well, default is only evaluated if needed; bar is always evaluated. What is wrong with the Python equivalent
result = default if bar is None else bar or if you prefer result = bar if bar is not None else default
Perhaps you didn't know about this construction?
Best wishes Rob Cliffe