Re: [Python-ideas] Start argument for itertools.accumulate() [Was: Proposal: A Reduce-Map Comprehension and a "last" builtin]

Well if you can get Raymond to agree on that too I suppose you can go ahead. Personally I'm -0 but I don't really write this kind of algorithmic code enough to know what's useful. I do think that the new parameter name is ugly. But maybe that's the point. On Sat, Apr 7, 2018 at 10:26 PM, Tim

Re: [Python-ideas] PEP 572: Statement-Local Name Bindings, take three!

On Sun, Apr 08, 2018 at 09:25:33PM +1000, Nick Coghlan wrote: > I was writing a new stdlib test case today, and thinking about how I > might structure it differently in a PEP 572 world, and realised that a > situation the next version of the PEP should discuss is this one: > > # Dict display

Re: [Python-ideas] PEP 572: Statement-Local Name Bindings, take three!

On 23 March 2018 at 20:01, Chris Angelico wrote: > Apologies for letting this languish; life has an annoying habit of > getting in the way now and then. > > Feedback from the previous rounds has been incorporated. From here, > the most important concern and question is: Is there

Re: [Python-ideas] PEP 572: Statement-Local Name Bindings, take three!

On Sun, Apr 8, 2018 at 8:01 AM, Steven D'Aprano wrote: > If we really wanted to keep the sublocal scoping, we could make > list/set/dict displays their own scope too. > > Personally, that's the only argument for sublocal scoping that I like > yet: what happens inside a

Re: [Python-ideas] Start argument for itertools.accumulate() [Was: Proposal: A Reduce-Map Comprehension and a "last" builtin]

Another bit of prior art: the Python itertoolz package also supplies `accumulate()`, with an optional `initial` argument. I stumbled into that when reading a Stackoverflow "how can I do Haskell's scanl in Python?" question.

Re: [Python-ideas] PEP 572: Statement-Local Name Bindings, take three!

# Dict display data = { key_a: local_a := 1, key_b: local_b := 2, key_c: local_c := 3, } Isn’t this a set display with local assignments and type annotations? :o) (I’m -1 on all of these ideas, btw. None help readability for me, and I read much more code than I

Re: [Python-ideas] Proposal: A Reduce-Map Comprehension and a "last" builtin

On 2018-04-05 21:18, Steven D'Aprano wrote: > (I don't understand why so many people have such an aversion to writing > functions and seek to eliminate them from their code.) > I think I am one of those people that have an aversion to writing functions! I hope you do not mind that I attempt

Re: [Python-ideas] Start argument for itertools.accumulate() [Was: Proposal: A Reduce-Map Comprehension and a "last" builtin]

[Guido] > Well if you can get Raymond to agree on that too I suppose you can go ahead. > Personally I'm -0 but I don't really write this kind of algorithmic code > enough to know what's useful. Actually, you do - but you don't _think_ of problems in these terms. Neither do I. For those who do:

[Python-ideas] Accepting multiple mappings as positional arguments to create dicts

Hi! I thought that maybe dict could accept several mappings as positional arguments, like this: class Dict4(dict): > def __init__(self, *args, **kwargs): > if len(args) > 1: > if not all([isinstance(arg, dict) for arg in args]): > raise TypeError('Dict4

Re: [Python-ideas] Start argument for itertools.accumulate() [Was: Proposal: A Reduce-Map Comprehension and a "last" builtin]

2018-04-08 8:19 GMT+03:00 Nick Coghlan : > A name like "first_result" would also make it clearer to readers that > passing that parameter has an impact on the length of the output > series (since you're injecting an extra result), and also that the > production of the first

Re: [Python-ideas] Start argument for itertools.accumulate() [Was: Proposal: A Reduce-Map Comprehension and a "last" builtin]

> On Apr 8, 2018, at 12:22 PM, Tim Peters wrote: > > [Guido] >> Well if you can get Raymond to agree on that too I suppose you can go ahead. >> Personally I'm -0 but I don't really write this kind of algorithmic code >> enough to know what's useful. > > Actually, you do -

Re: [Python-ideas] Start argument for itertools.accumulate() [Was: Proposal: A Reduce-Map Comprehension and a "last" builtin]

FYI: [Raymond] > ... > Q. Do other languages do it? > A. Numpy, no. R, no. APL, no. Mathematica, no. Haskell, yes. > >... > * https://www.haskell.org/hoogle/?hoogle=mapAccumL Haskell has millions of functions ;-) `mapAccumL` is a God-awful mixture of Python's map(), reduce(), and

Re: [Python-ideas] Proposal: A Reduce-Map Comprehension and a "last" builtin

Kyle Lahnakoski wrote: Consider Serhiy Storchaka's elegant solution, which I reformatted for readability smooth_signal = [ average for average in [0] for x in signal for average in [(1-decay)*average + decay*x] ] "Elegant" isn't the word I would use, more like "clever". Rather

Re: [Python-ideas] Start argument for itertools.accumulate() [Was: Proposal: A Reduce-Map Comprehension and a "last" builtin]

[Raymond] > The Bayesian world view isn't much different except they would > prefer "prior" instead of "initial" or "start" ;-) > > my_changing_beliefs = accumulate(stream_of_new_evidence, bayes_rule, > prior=what_i_used_to_think) > > Though the two analogies are cute, I'm not sure they tell

Re: [Python-ideas] Start argument for itertools.accumulate() [Was: Proposal: A Reduce-Map Comprehension and a "last" builtin]

> >>> list(accumulate([1, 2, 3])) > [11, 13, 16] Wow! I would have sworn that said [1, 3, 6] when I sent it. Damn Gmail ;-) > >>> list(accumulate([1, 2, 3], initial=10)) > [10, 11, 13, 16] ___ Python-ideas mailing list Python-ideas@python.org

Re: [Python-ideas] Start argument for itertools.accumulate() [Was: Proposal: A Reduce-Map Comprehension and a "last" builtin]

Raymond Hettinger wrote: For neither of those use case categories did I ever want an initial value and it would have been distracting to even had the option. For example, when doing a discounted cash flow analysis, I was taught to model the various flows as a single sequence of up and down

Re: [Python-ideas] Start argument for itertools.accumulate() [Was: Proposal: A Reduce-Map Comprehension and a "last" builtin]

> On Apr 8, 2018, at 6:43 PM, Tim Peters wrote: > >> My other common case for accumulate() is building cumulative >> probability distributions from probability mass functions (see the >> code for random.choice() for example, or typical code for a K-S test). > > So, a