Re: Stupid ways to spell simple code
On 30 June 2013 07:06, Chris Angelico ros...@gmail.com wrote: So, here's a challenge: Come up with something really simple, and write an insanely complicated - yet perfectly valid - way to achieve the same thing. Bonus points for horribly abusing Python's clean syntax in the process. This occurred to me out of the blue while working on something related. Here's a way to remove all instances of an element from an iterable. It's remarkably fast for it's course of action: from collections import deque from itertools import chain exhaust_iterable = deque(maxlen=0).extend def split_on(data, sentinel): chained = data = iter(data) while True: chunk = iter(chained.__next__, sentinel) yield chunk # Uses at least one item from chained, so chained and data are equivilant after this. # This is important as data is raw and thus will not get bogged down by pointless chain wrappings. # Yes, that is a premature optimisation. Go away. exhaust_iterable(chunk) # Throw StopIteration if not empty chained = chain([next(data)], data) def remove_all(iterable, victim): return list(chain.from_iterable(split_on(iterable, victim))) print(remove_all([1, 2, 1, 1, 0, 1, 2, 1, 1, 2, 2, 1, 0], 1)) and here it is again: from itertools import chain, repeat def remove_all(iterable, victim): iterable = iter(iterable) return list(chain.from_iterable(iter(chain([next(iterable)], iterable).__next__, victim) for _ in repeat(...))) print(remove_all([1, 2, 1, 1, 0, 1, 2, 1, 1, 2, 2, 1, 0], 1)) -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On 22:09 Mon 01 Jul , Steven D'Aprano wrote: On Mon, 01 Jul 2013 20:36:29 +0100, Marcin Szamotulski wrote: Here is another example which I came across when playing with generators, the first function is actually quite useful, the second generator is the whole fun: from functools import wraps def init(func): decorator which initialises the generator @wraps(func) def inner(*args, **kwargs): g = func(*args, **kwargs) g.send(None) return g return inner @init def gen(func): x = (yield) while True: x = (yield func(x)) now if you have function f def f(arg): return arg**2 then calling f(5) is the same as g = gen(f) g.send(5) I think you must be missing an important part of the trick, because calling f(5) returns 25. It's not: @gen def f(arg): return arg**2 because that raises TypeError. -- Steven -- http://mail.python.org/mailman/listinfo/python-list Sure it does, you're now supposed to use .send method instead of calling it but this is just different syntax. If you want to call it use this : def identity(func): @init def gen(func): x = (yield) while True: x = (yield func(x)) return gen(func).send Now you will get: @identity def f(a): a+1 ... f(0) 1 Best regards, Marcin -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On Tue, Jul 2, 2013 at 2:30 AM, Joshua Landau joshua.landau...@gmail.com wrote: Beautiful, see? Truly a work of art! I am awed. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On Sunday, June 30, 2013 8:06:35 AM UTC+2, Chris Angelico wrote:
There's a bit of a discussion on python-ideas that includes a function
that raises StopIteration. It inspired me to do something stupid, just
to see how easily I could do it...
On Sun, Jun 30, 2013 at 3:45 PM, Nick Coghlan ncogh...@gmail.com wrote:
Re: [Python-ideas] Iteration stopping syntax
def stop():
... raise StopIteration
Here's a much more insane way to spell that:
stop = (lambda: 0 and (yield 1))().__next__
So, here's a challenge: Come up with something really simple, and
write an insanely complicated - yet perfectly valid - way to achieve
the same thing. Bonus points for horribly abusing Python's clean
syntax in the process.
Go on, do your worst!
ChrisA
Here's a way to count items in a string.
def count(string, x):
return len(''.join(string)) - len(''.join(string).replace(x, '')) / len(x)
--
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Re: Stupid ways to spell simple code
On 2013-06-30, Chris Angelico ros...@gmail.com wrote:
So, here's a challenge: Come up with something really simple,
and write an insanely complicated - yet perfectly valid - way
to achieve the same thing. Bonus points for horribly abusing
Python's clean syntax in the process.
Go on, do your worst!
I've often thought it was redundant for Python to support 'if'
when it has dictionaries, cf the rationale for having no
'switch'.
valid_name = None
while not valid_name:
name = input(Enter your name: )
valid_name = {
True: lambda: print(No name longer than 20 letters.),
False: lambda: True,
}[len(name) 20]()
Much better.
--
Neil Cerutti
--
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Re: Stupid ways to spell simple code
On Mon, Jul 1, 2013 at 10:59 PM, Neil Cerutti ne...@norwich.edu wrote:
On 2013-06-30, Chris Angelico ros...@gmail.com wrote:
So, here's a challenge: Come up with something really simple,
and write an insanely complicated - yet perfectly valid - way
to achieve the same thing. Bonus points for horribly abusing
Python's clean syntax in the process.
Go on, do your worst!
I've often thought it was redundant for Python to support 'if'
when it has dictionaries, cf the rationale for having no
'switch'.
valid_name = None
while not valid_name:
name = input(Enter your name: )
valid_name = {
True: lambda: print(No name longer than 20 letters.),
False: lambda: True,
}[len(name) 20]()
Much better.
Good! Good! But, wh. Wh.
def get_name():
while True:
name = input(Enter your name: )
yield {
True: lambda: print(No name longer than 20 letters.),
False: lambda: name,
}[len(name) 20]()
name = next(filter(None,get_name()))
ChrisA
--
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Re: Stupid ways to spell simple code
On 1 July 2013 14:14, Chris Angelico ros...@gmail.com wrote:
On Mon, Jul 1, 2013 at 10:59 PM, Neil Cerutti ne...@norwich.edu wrote:
On 2013-06-30, Chris Angelico ros...@gmail.com wrote:
So, here's a challenge: Come up with something really simple,
and write an insanely complicated - yet perfectly valid - way
to achieve the same thing. Bonus points for horribly abusing
Python's clean syntax in the process.
Go on, do your worst!
I've often thought it was redundant for Python to support 'if'
when it has dictionaries, cf the rationale for having no
'switch'.
valid_name = None
while not valid_name:
name = input(Enter your name: )
valid_name = {
True: lambda: print(No name longer than 20 letters.),
False: lambda: True,
}[len(name) 20]()
Much better.
Good! Good! But, wh. Wh.
def get_name():
while True:
name = input(Enter your name: )
yield {
True: lambda: print(No name longer than 20 letters.),
False: lambda: name,
}[len(name) 20]()
name = next(filter(None,get_name()))
Oh, cruel. But you can do worse. Who needs while when you have
filter(iter(FUNCTION, object()))?
def get_name():
name = input(Enter your name: )
return [
lambda: name,
lambda: print(No name longer than 20 letters.),
][len(name) 20]()
name = next(filter(None, iter(get_name, object(
But who needs *any* of this! Defining functions is so old-hat. It's
all already in the standard library (using only assignments and function-calls):
from functools import partial
from operator import getitem, ge, methodcaller
from itertools import compress, tee
apply = methodcaller(__call__)
ret_true = partial(getitem, [True], 0)
print_invalid = partial(print, No name longer than 20 letters.)
inputs = iter(partial(input, Enter your name: ), ...)
inputs, valid = tee(inputs)
valid = map(len, valid)
valid = map(partial(ge, 20), valid)
side_effect_valid = map(partial(getitem, [print_invalid, ret_true]), valid)
side_effect_valid = map(apply, side_effect_valid)
valid_inputs = compress(inputs, side_effect_valid)
name = next(valid_inputs)
Which can be neatly expressed as two statements (I'm struggling to
got it to one without those evil lambdas):
from functools import partial
from operator import getitem, ge, methodcaller
from itertools import compress, tee
inputs, valid = tee(iter(partial(input, Enter your name: ), ...))
name = next(
compress(
inputs,
map(
methodcaller(__call__),
map(
partial(
getitem,
[
partial(print, No name longer than 20 letters.),
partial(getitem, [True], 0)
]
),
map(
partial(ge, 20),
map(len, valid)
)
)
)
)
)
Beautiful, see?
Of course, the most powerful function deals with this much more quickly:
exec(
while True:
name = input(Enter your name: )
if len(name) = 20:
break
else:
print(No name longer than 20 letters.)
)
--
http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On 17:30 Mon 01 Jul , Joshua Landau wrote:
On 1 July 2013 14:14, Chris Angelico ros...@gmail.com wrote:
On Mon, Jul 1, 2013 at 10:59 PM, Neil Cerutti ne...@norwich.edu wrote:
On 2013-06-30, Chris Angelico ros...@gmail.com wrote:
So, here's a challenge: Come up with something really simple,
and write an insanely complicated - yet perfectly valid - way
to achieve the same thing. Bonus points for horribly abusing
Python's clean syntax in the process.
Go on, do your worst!
I've often thought it was redundant for Python to support 'if'
when it has dictionaries, cf the rationale for having no
'switch'.
valid_name = None
while not valid_name:
name = input(Enter your name: )
valid_name = {
True: lambda: print(No name longer than 20 letters.),
False: lambda: True,
}[len(name) 20]()
Much better.
Good! Good! But, wh. Wh.
def get_name():
while True:
name = input(Enter your name: )
yield {
True: lambda: print(No name longer than 20 letters.),
False: lambda: name,
}[len(name) 20]()
name = next(filter(None,get_name()))
Oh, cruel. But you can do worse. Who needs while when you have
filter(iter(FUNCTION, object()))?
def get_name():
name = input(Enter your name: )
return [
lambda: name,
lambda: print(No name longer than 20 letters.),
][len(name) 20]()
name = next(filter(None, iter(get_name, object(
But who needs *any* of this! Defining functions is so old-hat. It's
all already in the standard library (using only assignments and
function-calls):
from functools import partial
from operator import getitem, ge, methodcaller
from itertools import compress, tee
apply = methodcaller(__call__)
ret_true = partial(getitem, [True], 0)
print_invalid = partial(print, No name longer than 20 letters.)
inputs = iter(partial(input, Enter your name: ), ...)
inputs, valid = tee(inputs)
valid = map(len, valid)
valid = map(partial(ge, 20), valid)
side_effect_valid = map(partial(getitem, [print_invalid, ret_true]), valid)
side_effect_valid = map(apply, side_effect_valid)
valid_inputs = compress(inputs, side_effect_valid)
name = next(valid_inputs)
Which can be neatly expressed as two statements (I'm struggling to
got it to one without those evil lambdas):
from functools import partial
from operator import getitem, ge, methodcaller
from itertools import compress, tee
inputs, valid = tee(iter(partial(input, Enter your name: ), ...))
name = next(
compress(
inputs,
map(
methodcaller(__call__),
map(
partial(
getitem,
[
partial(print, No name longer than 20 letters.),
partial(getitem, [True], 0)
]
),
map(
partial(ge, 20),
map(len, valid)
)
)
)
)
)
Beautiful, see?
Of course, the most powerful function deals with this much more quickly:
exec(
while True:
name = input(Enter your name: )
if len(name) = 20:
break
else:
print(No name longer than 20 letters.)
)
--
http://mail.python.org/mailman/listinfo/python-list
Here is another example which I came across when playing with
generators, the first function is actually quite useful, the second
generator is the whole fun:
from functools import wraps
def init(func):
decorator which initialises the generator
@wraps(func)
def inner(*args, **kwargs):
g = func(*args, **kwargs)
g.send(None)
return g
return inner
@init
def gen(func):
x = (yield)
while True:
x = (yield func(x))
now if you have function f
def f(arg):
return arg**2
then calling f(5) is the same as
g = gen(f)
g.send(5)
I wrote a blog post where I did include this as a `useless` example:
http://pycorner.herokuapp.com/blog/5
Best regards,
Marcin
--
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Re: Stupid ways to spell simple code
On Mon, 01 Jul 2013 20:36:29 +0100, Marcin Szamotulski wrote: Here is another example which I came across when playing with generators, the first function is actually quite useful, the second generator is the whole fun: from functools import wraps def init(func): decorator which initialises the generator @wraps(func) def inner(*args, **kwargs): g = func(*args, **kwargs) g.send(None) return g return inner @init def gen(func): x = (yield) while True: x = (yield func(x)) now if you have function f def f(arg): return arg**2 then calling f(5) is the same as g = gen(f) g.send(5) I think you must be missing an important part of the trick, because calling f(5) returns 25. It's not: @gen def f(arg): return arg**2 because that raises TypeError. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
Steven D'Aprano於 2013年7月2日星期二UTC+8上午6時09分18秒寫道： On Mon, 01 Jul 2013 20:36:29 +0100, Marcin Szamotulski wrote: Here is another example which I came across when playing with generators, the first function is actually quite useful, the second generator is the whole fun: from functools import wraps def init(func): decorator which initialises the generator @wraps(func) def inner(*args, **kwargs): g = func(*args, **kwargs) g.send(None) return g return inner @init def gen(func): x = (yield) while True: x = (yield func(x)) now if you have function f def f(arg): return arg**2 then calling f(5) is the same as g = gen(f) g.send(5) I think you must be missing an important part of the trick, because calling f(5) returns 25. It's not: @gen def f(arg): return arg**2 because that raises TypeError. -- Steven Lets be serious about generators and iterators. A generator can be used only once in a program is different from a a generator method of a class that can produce several instances with generators of the same kind but operated in each instance of the class. -- http://mail.python.org/mailman/listinfo/python-list
Stupid ways to spell simple code
There's a bit of a discussion on python-ideas that includes a function that raises StopIteration. It inspired me to do something stupid, just to see how easily I could do it... On Sun, Jun 30, 2013 at 3:45 PM, Nick Coghlan ncogh...@gmail.com wrote: Re: [Python-ideas] Iteration stopping syntax def stop(): ... raise StopIteration Here's a much more insane way to spell that: stop = (lambda: 0 and (yield 1))().__next__ So, here's a challenge: Come up with something really simple, and write an insanely complicated - yet perfectly valid - way to achieve the same thing. Bonus points for horribly abusing Python's clean syntax in the process. Go on, do your worst! ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On 30 June 2013 07:06, Chris Angelico ros...@gmail.com wrote: There's a bit of a discussion on python-ideas that includes a function that raises StopIteration. It inspired me to do something stupid, just to see how easily I could do it... On Sun, Jun 30, 2013 at 3:45 PM, Nick Coghlan ncogh...@gmail.com wrote: Re: [Python-ideas] Iteration stopping syntax def stop(): ... raise StopIteration Here's a much more insane way to spell that: stop = (lambda: 0 and (yield 1))().__next__ So, here's a challenge: Come up with something really simple, and write an insanely complicated - yet perfectly valid - way to achieve the same thing. Bonus points for horribly abusing Python's clean syntax in the process. Go on, do your worst! You'll have to excuse me -- I'm writing a library to do just that. I'll be done in a few weeks. -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On 30Jun2013 16:06, Chris Angelico ros...@gmail.com wrote: | So, here's a challenge: Come up with something really simple, and | write an insanely complicated - yet perfectly valid - way to achieve | the same thing. Bonus points for horribly abusing Python's clean | syntax in the process. _Must_ you turn this into comp.lang.perl? Once I was JAPH... -- Cameron Simpson c...@zip.com.au Yes, sometimes Perl looks like line-noise to the uninitiated, but to the seasoned Perl programmer, it looks like checksummed line-noise with a mission in life.- The Llama Book -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On Sunday, June 30, 2013 1:06:35 AM UTC-5, Chris Angelico wrote: So, here's a challenge: Come up with something really simple, and write an insanely complicated - yet perfectly valid - way to achieve the same thing. Bonus points for horribly abusing Python's clean syntax in the process. Chris, i'm sorry, but your challenge is decades too late. If you seek amusement you need look no further than the Python stdlib. If you REALLY want to be amused, peruse the idlelib -- not only is the code obfuscated, it also breaks PEP8 and the PYTHON ZEN many times over. -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On 30 June 2013 15:58, Rick Johnson rantingrickjohn...@gmail.com wrote: Chris, i'm sorry, but your challenge is decades too late. If you seek amusement you need look no further than the Python stdlib. If you REALLY want to be amused, peruse the idlelib -- not only is the code obfuscated, it also breaks PEP8 and the PYTHON ZEN many times over. To translate: Not only is the code impossible to read, inefficient and unmaintainable whilst being only shallowly correct, but, *GASP* it sometimes *breaks* semi-arbitrary code *style* *suggestions*! How dare it!‽ -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On Mon, Jul 1, 2013 at 1:08 AM, Joshua Landau joshua.landau...@gmail.com wrote: On 30 June 2013 15:58, Rick Johnson rantingrickjohn...@gmail.com wrote: Chris, i'm sorry, but your challenge is decades too late. If you seek amusement you need look no further than the Python stdlib. If you REALLY want to be amused, peruse the idlelib -- not only is the code obfuscated, it also breaks PEP8 and the PYTHON ZEN many times over. To translate: Not only is the code impossible to read, inefficient and unmaintainable whilst being only shallowly correct, but, *GASP* it sometimes *breaks* semi-arbitrary code *style* *suggestions*! How dare it!‽ Yeah, I cannot seriously imagine that the stdlib does anything like the example I gave :) Pity nobody else is offering further examples, I thought this might be a fun thread. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On Sun, Jun 30, 2013 at 9:20 AM, Chris Angelico ros...@gmail.com wrote: Yeah, I cannot seriously imagine that the stdlib does anything like the example I gave :) Pity nobody else is offering further examples, I thought this might be a fun thread. Well, there is the this module. But its code is not *that* obfuscated, and maintainability is not really an issue there since it is short and does nothing of actual importance. -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On Sun, 30 Jun 2013 16:06:35 +1000, Chris Angelico wrote:
So, here's a challenge: Come up with something really simple, and write
an insanely complicated - yet perfectly valid - way to achieve the same
thing. Bonus points for horribly abusing Python's clean syntax in the
process.
Here's a trivially stupid way to find the length of an iterable:
sum(1 for obj in iterable)
(except it isn't actually stupid, if the iterable is an iterator, and you
don't mind consuming it to find out home many items it had). This leads
to an obvious obfuscation:
sum(('.' for obj in iterable), '').count('.')
but sadly Python, in a rare case of protecting you from shooting your own
foot off, doesn't allow this. Never mind, we can defeat the safety catch
on sum() and complicate the code at the same time:
sum(('.' for obj in iterable), type('S', (),
{'__add__': lambda self, o: o})()).count('.')
Obfuscated *and* quadratic performance. Do I win?
Wait, I can beat that. Sorting is too trivial in Python:
alist.sort()
Pfft! Where's the challenge in that? Let's use an O(n!) algorithm for
sorting -- yes, n factorial -- AND abuse a generator expression for its
side effect. As a bonus, we use itertools, and just for the lulz, I
obfuscate as many of the names as I can:
from random import shuffle as OOO00O
from itertools import takewhile as OO0O0O, count as O0OO0O
OO0O00 = range(5)
list(OO0O0O(lambda O: any(O[O0] O[O0-1] for O0 in
range(1, sum(('O' for O in O), type('O', (),
{'__add__': lambda O0O, OO0: OO0})()).count('O'))),
(OOO00O(OO0O00) or OO0O00 for O in O0OO0O([0]
--
Steven
--
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Re: Stupid ways to spell simple code
In article 51d06cb6$0$2$c3e8da3$54964...@news.astraweb.com, Steven D'Aprano steve+comp.lang.pyt...@pearwood.info wrote: On Sun, 30 Jun 2013 16:06:35 +1000, Chris Angelico wrote: So, here's a challenge: Come up with something really simple, and write an insanely complicated - yet perfectly valid - way to achieve the same thing. Bonus points for horribly abusing Python's clean syntax in the process. Here's a trivially stupid way to find the length of an iterable: sum(1 for obj in iterable) That's how you would do it in a map-reduce environment :-) -- http://mail.python.org/mailman/listinfo/python-list
Re: Stupid ways to spell simple code
On 30 June 2013 18:36, Steven D'Aprano
steve+comp.lang.pyt...@pearwood.info wrote:
Pfft! Where's the challenge in that? Let's use an O(n!) algorithm for
sorting -- yes, n factorial -- AND abuse a generator expression for its
side effect. As a bonus, we use itertools, and just for the lulz, I
obfuscate as many of the names as I can:
from random import shuffle as OOO00O
from itertools import takewhile as OO0O0O, count as O0OO0O
OO0O00 = range(5)
list(OO0O0O(lambda O: any(O[O0] O[O0-1] for O0 in
range(1, sum(('O' for O in O), type('O', (),
{'__add__': lambda O0O, OO0: OO0})()).count('O'))),
(OOO00O(OO0O00) or OO0O00 for O in O0OO0O([0]
I've got to say -- that last line got me for quite a while, especially
as the list of lists was returning a list of sorted lists!
For obfuscation, though, you want unicode. It's much harder to reason
about code that you can't read.
from itertools import count as æ, permutations as Æ, starmap as ð
[globals().setdefault(%c%sum(ø.encode()),ß)for ø,ß in
vars(__builtins__).items()if ø!=vars]
sorted = lambda ħ:ƿ(ƞ for ı in
φ(ƴ(lambda:ħ,æ),ń(0,ń(ħ)**(len(ħ)*2-1)*len(ħ)))for ƞ in Æ(ħ)if
ǂ(()).__eq__((ŕ(ð(ǂ(Ƽ(ƞ).pop()).__rpow__,φ(ŕ(œ(ƞ,ƴ(lambda:0,ħ)),()),1))),ħ),ı))[::-1]
print(sorted([4, -3, 4, 2, -1]))
This only works for integers (including negatives) and some things
that seem to do nothing but slow it down are needed to cover special
cases. This one takes about 3½ minutes on my computer -- it's got a
runtime efficiency of something along the lines of O( (L!) * ((L)**i)
) for i being related to the elements in the list and L being the
length of the list.
That said, it's rather OK at sorting [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0].
I know this is more oriented towards obfuscation of code than
obfuscation of technique, but --as I said-- I'm writing a library for
that. I'll be back when it's ready.
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