In case someone is actually going to execute the code, there is a bug:
`set` need to be wrapped in `len` for criteria args.
> On 15 Nov 2023, at 20:13, Dom Grigonis wrote:
>
>
> The specific situation was related to truth values and following out of that
> my considerations regarding
The specific situation was related to truth values and following out of that my
considerations regarding equivalent of all and any for counting `truths`.
So one of the specific examples:
class Publisher:
def __init__(self):
self.subscribers = dict()
def subscribe(self, sub,
On 2023-11-15 12:26:32 +0200, Dom Grigonis wrote:
>
> Thank you,
>
>
> test2 = [True] * 100 + [False] * 2
> test2i = list(range(100))
>
> %timeit len(set(test2i)) == 1 # 1.6 µs ± 63.6 ns per loop (mean ± std. dev.
> of 7 runs, 1,000,000 loops each)
> %timeit all(test2) # 386 ns
Thank you,
test2 = [True] * 100 + [False] * 2
test2i = list(range(100))
%timeit len(set(test2i)) == 1 # 1.6 µs ± 63.6 ns per loop (mean ± std. dev.
of 7 runs, 1,000,000 loops each)
%timeit all(test2) # 386 ns ± 9.58 ns per loop (mean ± std. dev.
of 7 runs, 1,000,000 loops each)
On 2023-11-14 00:11:30 +0200, Dom Grigonis via Python-list wrote:
> Benchmarks:
> test1 = [False] * 100 + [True] * 2
> test2 = [True] * 100 + [False] * 2
>
> TIMER.repeat([
> lambda: xor(test1), # 0.0168
> lambda: xor(test2), # 0.0172
> lambda: xor_ss(test1), # 0.1392
>
r the
>> non-standard evaluation in R where you can arrange for lots of your data to
>> not be interpreted till absolutely needed.
>> -Original Message-
>> From: Dom Grigonis
>> Sent: Monday, November 13, 2023 10:12 PM
>> To: avi.e.gr...@gmail.com
>>
n R where you can arrange for lots of your data to not
be interpreted till absolutely needed.
-Original Message-
From: Dom Grigonis
Sent: Monday, November 13, 2023 10:12 PM
To: avi.e.gr...@gmail.com
Cc: Grant Edwards ; Python
Subject: Re: xor operator (DEPRECATED)
Fair point. Ho
ubject: Re: xor operator (DEPRECATED)
Fair point. However, I gave it a shot for the following reason:
I couldn’t find a way to make such performant function. Using python builtin
components still ends up several times slower than builtin `all`. Cython or
numba or similar is not an option
e up with an amazing number of ideas including for
> "useful" functions or features but I find the vast majority would rarely be
> used as nobody remembers it is available and some fairly simple method using
> other functions can easily be cobbled together.
>
> -Original Message
other functions can easily be cobbled together.
-Original Message-
From: Python-list On
Behalf Of Grant Edwards via Python-list
Sent: Monday, November 13, 2023 8:19 PM
To: python-list@python.org
Subject: Re: xor operator
On 2023-11-14, Dom Grigonis via Python-list wrote:
>
>> Exc
On 2023-11-14, Dom Grigonis via Python-list wrote:
>
>> Except the 'any' and 'all' builtins are _exactly_ the same as bitwise
>> or and and applided to many bits. To do something "in line" with that
>> using the 'xor' operator would return True for an odd num
On Tue, 14 Nov 2023 at 11:40, Chris Angelico wrote:
> Here's a couple of excellent videos on error correction, and you'll
> see XOR showing up as a crucial feature:
>
> https://www.youtube.com/watch?v=X8jsijhllIA
> https://www.youtube.com/watch?v=h0jloehRKas
>
I just flipped through that
On 14/11/2023 00:33, Mats Wichmann via Python-list wrote:
> Hardware and software people may have somewhat different views of xor
I've come at it from both sides. I started life as a telecomms
technician and we learned about xor in the context of switching
and relays and xor was a wiring
On Tue, 14 Nov 2023 at 12:02, Dom Grigonis via Python-list
wrote:
> As I am here, I will dare to ask if there is no way that `sign` function is
> going to be added to `math` or `builtins`.
>
https://docs.python.org/3/library/math.html#math.copysign
ChrisA
--
I agree, from perspective of standard `all` and `any` use cases this does not
seem very useful.
However, in my experience it has its usages. E.g.:
* If sum(map(bool, iterable) [> | <] n can be useful. Counting dead processes
and similar, optimisation problems where need to re-initialise if less
On Tue, 14 Nov 2023 at 11:29, Dom Grigonis via Python-list
wrote:
>
>
> > Except the 'any' and 'all' builtins are _exactly_ the same as bitwise
> > or and and applided to many bits. To do something "in line" with that
> > using the 'xor' operator would ret
builtins are used.
>
> Except the 'any' and 'all' builtins are _exactly_ the same as bitwise
> or and and applided to many bits. To do something "in line" with that
> using the 'xor' operator would return True for an odd number of True
> values and False for an even Number of True values.
>
> --
> Grant
> --
> https://mail.python.org/mailman/listinfo/python-list
>
--
https://mail.python.org/mailman/listinfo/python-list
On 11/13/23 16:24, Dom Grigonis via Python-list wrote:
I am not arguing that it is a generalised xor.
I don’t want anything, I am just gauging if it is specialised or if there is a
need for it. So just thought could suggest it as I have encountered such need
several times already.
It is
> Except the 'any' and 'all' builtins are _exactly_ the same as bitwise
> or and and applided to many bits. To do something "in line" with that
> using the 'xor' operator would return True for an odd number of True
> values and False for an even Number of True values.
Fair
s. This is more in line
> with cases that `any` and `all` builtins are used.
Except the 'any' and 'all' builtins are _exactly_ the same as bitwise
or and and applided to many bits. To do something "in line" with that
using the 'xor' operator would return True for an odd number of Tru
I am not arguing that it is a generalised xor.
I don’t want anything, I am just gauging if it is specialised or if there is a
need for it. So just thought could suggest it as I have encountered such need
several times already.
It is fairly clear by now that it is not a common one given it took
On Tue, 14 Nov 2023 at 10:00, Dom Grigonis via Python-list
wrote:
>
> I am not asking. Just inquiring if the function that I described could be
> useful for more people.
>
> Which is: a function with API that of `all` and `any` and returns `True` if
> specified number of elements is True.
>
>
I am not asking. Just inquiring if the function that I described could be
useful for more people.
Which is: a function with API that of `all` and `any` and returns `True` if
specified number of elements is True.
It is not a generalised `xor` in strict programatic space. I.e. NOT bitwise xor
On 2023-11-13, Dom Grigonis via Python-list wrote:
> Hi All,
>
> I think it could be useful to have `xor` builtin, which has API similar to
> the one of `any` and `all`.
>
> * Also, it could have optional second argument `n=1`, which
> * indicates how many positives indicates `True` return. For
Benchmarks:
test1 = [False] * 100 + [True] * 2
test2 = [True] * 100 + [False] * 2
TIMER.repeat([
lambda: xor(test1), # 0.0168
lambda: xor(test2), # 0.0172
lambda: xor_ss(test1), # 0.1392
lambda: xor_ss(test2), # 0.0084
lambda: xor_new(test1), # 0.0116
lambda:
On Tue, 14 Nov 2023 at 08:57, Axel Reichert via Python-list
wrote:
>
> Barry writes:
>
> > I do not understand how xor(iterator) works.
> > I thought xor takes exactly 2 args.
>
> See
>
> https://mathworld.wolfram.com/XOR.html
>
> for some background (I was not aware of any generalizations for
Barry writes:
> I do not understand how xor(iterator) works.
> I thought xor takes exactly 2 args.
See
https://mathworld.wolfram.com/XOR.html
for some background (I was not aware of any generalizations for more
than 2 arguments either).
> I also do not understand how xor can be short
xor([True, False, False, False], n=1)
xor([False, False, False, True], n=1)
Both of the above would evaluate to true.
Well, it depends how you interpret it.
In binary case it reads: “exclusively one positive bit or the other, but not
both”
In this case one could read: “exclusively one positive
On 2023-11-13 21:03, Barry via Python-list wrote:
On 13 Nov 2023, at 17:48, Dom Grigonis wrote:
Short circuiting happens, when:
xor([True, True, False, False], n=1)
At index 1 it is clear that the answer is false.
Can you share an example with 4 values that is true?
And explain why it is
I don't think an exclusive-or/truthy-entries-count-checker needs to be a
builtin by any stretch.
>>> def xor( iterable, n = 1 ):
... return sum( map( bool, iterable ) ) == n
Or if you insist on short circuiting:
>>> def xor_ss( iterable, n = 1 ):
... for intermediate in
> On 13 Nov 2023, at 17:48, Dom Grigonis wrote:
>
> Short circuiting happens, when:
> xor([True, True, False, False], n=1)
> At index 1 it is clear that the answer is false.
Can you share an example with 4 values that is true?
And explain why it is xor.
Barry
--
Well yes, I don’t think naming is very accurate. If iterable has 2 elements,
then it is `xor`, otherwise it is something else - it checks the number of
truth values in iterable.
Short circuiting happens, when:
xor([True, True, False, False], n=1)
At index 1 it is clear that the answer is false.
> On 13 Nov 2023, at 15:16, Dom Grigonis via Python-list
> wrote:
>
> I think it could be useful to have `xor` builtin, which has API similar to
> the one of `any` and `all`.
I do not understand how xor(iterator) works.
I thought xor takes exactly 2 args.
I also do not understand how xor
Hi All,
I think it could be useful to have `xor` builtin, which has API similar to the
one of `any` and `all`.
* Also, it could have optional second argument `n=1`, which indicates how many
positives indicates `True` return.
* For complete flexibility 3rd argument could indicate if `the
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