terrible programmers: my god, it's full of chars

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PleasingFungus: Oct 10, 2012; idiot asshole bitch who should fuck off

sorry

it's worth noting that the explanation in my last post is still wrong, I... think. the conditionals are definitely being evaluated top-to-bottom, but something is traveling bottom-to-top; otherwise how did (WATER, ZEBRA) get into the innermost loop?

functional programming is hard

# ? Jul 24, 2013 05:34

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# ? May 16, 2024 11:30

coffeetable: Feb 5, 2006; TELL ME AGAIN HOW GREAT BRITAIN WOULD BE IF IT WAS RULED BY THE MERCILESS JACKBOOT OF PRINCE CHARLES

YES I DO TALK TO PLANTS ACTUALLY

if i were forced to reformat that code, i'd probably go with

code:

# gently caress your 80 characters

return next((WATER, ZEBRA)
              	for (red, green, ivory, yellow, blue)			  	in c(orderings) 	if imright(green, ivory)
                for (Englishman, Spaniard, Ukranian, Japanese, Norwegian) 	in c(orderings) 	if (Englishman is red) 	and (Norwegian is first) 	and nextto(Norwegian, blue)
                for (coffee, tea, milk, oj, WATER) 				in c(orderings) 	if (coffee is green) 	and (Ukranian is tea) 		and (milk is middle)
                for (OldGold, Kools, Chesterfields, LuckyStrike, Parliaments) 	in c(orderings) 	if (Kools is yellow) 	and (LuckyStrike is oj) 	and (Japanese is Parliaments)
                for (dog, snails, fox, horse, ZEBRA) 				in c(orderings)		if (Spaniard is dog) 	and (OldGold is snails) 	and nextto(Chesterfields, fox) 		and nextto(Kools, horse)
                )

but my god there has to be a better way, probably involving pulling each of those lines out into their own function so you could see how they interact

coffeetable fucked around with this message at 06:02 on Jul 24, 2013

# ? Jul 24, 2013 05:57

qntm: Jun 17, 2009

the most readable form doesn't use list comprehensions

# ? Jul 24, 2013 09:34

qntm: Jun 17, 2009

Python code:

for (red, green, ivory, yellow, blue) in c(orderings):
  if not imright(green, ivory): continue
  for (Englishman, Spaniard, Ukranian, Japanese, Norwegian) in c(orderings):
    if not Englishman is red       : continue
    if not Norwegian is first      : continue
    if not nextto(Norwegian, blue) : continue
    for (coffee, tea, milk, oj, WATER) in c(orderings):
      if not coffee is green : continue
      if not Ukranian is tea : continue
      if not milk is middle  : continue
      for (OldGold, Kools, Chesterfields, LuckyStrike, Parliaments) in c(orderings):
        if not Kools is yellow         : continue
        if not LuckyStrike is oj       : continue
        if not Japanese is Parliaments : continue
        for (dog, snails, fox, horse, ZEBRA) in c(orderings):
          if not Spaniard is dog            : continue
          if not OldGold is snails          : continue
          if not nextto(Chesterfields, fox) : continue
          if not nextto(Kools, horse)       : continue
          return (WATER, ZEBRA)

hope this makes things clear

# ? Jul 24, 2013 09:52

Symbolic Butt: Mar 22, 2009; (_!_); Buglord

anyway here's the entire code:

Python code:

import itertools
import time

def imright(h1, h2):
    "House h1 is immediately right of h2 if h1-h2 == 1."
    return h1-h2 == 1

def nextto(h1, h2):
    "Two houses are next to each other if they differ by 1."
    return abs(h1-h2) == 1

def zebra_puzzle():
    "Return a tuple (WATER, ZEBRA indicating their house numbers."
    houses = first, _, middle, _, _ = [1, 2, 3, 4, 5]
    orderings = list(itertools.permutations(houses)) # 1
    return next((WATER, ZEBRA)
                for (red, green, ivory, yellow, blue) in c(orderings)
                if imright(green, ivory)
                for (Englishman, Spaniard, Ukranian, Japanese, Norwegian) in c(orderings)
                if Englishman is red
                if Norwegian is first
                if nextto(Norwegian, blue)
                for (coffee, tea, milk, oj, WATER) in c(orderings)
                if coffee is green
                if Ukranian is tea
                if milk is middle
                for (OldGold, Kools, Chesterfields, LuckyStrike, Parliaments) in c(orderings)
                if Kools is yellow
                if LuckyStrike is oj
                if Japanese is Parliaments
                for (dog, snails, fox, horse, ZEBRA) in c(orderings)
                if Spaniard is dog
                if OldGold is snails
                if nextto(Chesterfields, fox)
                if nextto(Kools, horse)
                )

def c(sequence):
    c.starts += 1
    for item in sequence:
        c.items += 1
        yield item

def instrument_fn(fn, *args):
    c.starts, c.items = 0, 0
    result = fn(*args)
    print('%s got %s with %5d iters over %7d items'%(
        fn.__name__, result, c.starts, c.items))

c and instrument_fn are just some temporary debug functions for counting the number of calls and doesn't really matter (it was just an excuse for him to introduce some new stuff like the unpacking notation)

here's one way to rewrite the function but it's pretty much the same thing qntm did and I didn't see his post before. :rolleyes:

Python code:

def zebra_puzzle():
    houses = first, _, middle, _, _ = [1, 2, 3, 4, 5]
    orderings = list(itertools.permutations(houses))
    for (red, green, ivory, yellow, blue) in orderings:
        if imright(green, ivory):
            for (Englishman, Spaniard, Ukranian, Japanese, Norwegian) in orderings:
                if Englishman is red and Norwegian is first and nextto(Norwegian, blue):
                    for (coffee, tea, milk, oj, WATER) in orderings:
                        if coffee is green and Ukranian is tea and milk is middle:
                            for (OldGold, Kools, Chesterfields, LuckyStrike, Parliaments) in orderings:
                                if Kools is yellow and LuckyStrike is oj and Japanese is Parliaments:
                                    for (dog, snails, fox, horse, ZEBRA) in orderings:
                                        if Spaniard is dog and OldGold is snails and nextto(Chesterfields, fox) and nextto(Kools, horse):
                                            return (WATER, ZEBRA)

geez, so much indentation.

I don't think in this case the comprehension would be faster because he's only getting the first possible solution but even so it looks better to me.

a similar brute force case where it would matter is in this problem. here's one of my first attempts before figuring the real trick:

Python code:

from itertools import combinations

COUNT_MODULO = 1000000009

def count(seq, bound):
    lseq = len(seq)
    return len({hash(subseq[:i] + (new_element, ) + subseq[i:])
                for subseq in set(combinations(seq, lseq-1))
                for i in xrange(lseq)
                for new_element in xrange(1, bound+1)}) % COUNT_MODULO

using the set comprehension here is considerably faster than going with something like

Python code:

def count(seq, bound):
    lseq = len(seq)
    s = set()
    for subseq in set(combinations(seq, lseq-1)):
        for i in xrange(lseq):
            for new_element in xrange(1, bound+1):
                s.add(hash(subseq[:i] + (new_element,) + subseq[i:]))
    return len(s) % COUNT_MODULO

but I guess from now on I'll stick with not using those "impossible to write in a 79 characters line" comprehensions because it's obfuscating the code and being a kind of premature optimization. it's just that I'm so used to it.

# ? Jul 24, 2013 14:11

MeruFM: Jul 27, 2010

This is definitely the most complex a single list comprehension should be

code:

for user in [post.user() for post in thread if poo poo(post) is True]:
    user.ban()

# ? Jul 24, 2013 17:01

MeruFM: Jul 27, 2010

Symbolic Butt posted:

code:

# ? Jul 24, 2013 17:20

FamDav: Mar 29, 2008

Can't you just use prolog

# ? Jul 24, 2013 17:21

Symbolic Butt: Mar 22, 2009; (_!_); Buglord

oh hey that for-if ladder actually looks kinda cool when you put it this way

*farts*

I wonder if the zebra puzzle is one of those things that can be done particularly well in prolog from what I hear people say about it

edit: what the gently caress FamDav

# ? Jul 24, 2013 17:24

prefect: Sep 11, 2001; No one, Woodhouse.
No one.; Dead Man’s Band

Symbolic Butt posted:

geez, so much indentation.

speaking only for myself, there's no such thing as "too much indentation". i consider it a built-in requirement of the code, even when i'm not using python

# ? Jul 24, 2013 17:30

prefect: Sep 11, 2001; No one, Woodhouse.
No one.; Dead Man’s Band

FamDav posted:

Can't you just use prolog

Symbolic Butt posted:

I wonder if the zebra puzzle is one of those things that can be done particularly well in prolog from what I hear people say about it

edit: what the gently caress FamDav

somebody light the tef-signal; i want to see what prolog would look like :allears:

# ? Jul 24, 2013 17:31

uG: Apr 23, 2003; by Ralp

http://rosettacode.org/wiki/Zebra_puzzle#Prolog

# ? Jul 24, 2013 17:36

prefect: Sep 11, 2001; No one, Woodhouse.
No one.; Dead Man’s Band

uG posted:

http://rosettacode.org/wiki/Zebra_puzzle#Prolog

thanks

now if only i can figure out what's actually happening

(it definitely looks like this is something prolog is good at; much less convoluted than a lot of other languages)

# ? Jul 24, 2013 17:45

Elder Postsman: Aug 30, 2000; i used hot bot to search for "teens"

PleasingFungus posted:

that is extremely silly, and certainly bad practice, but I can't bring myself to be upset about it. (the teddy in your av probably helps. )

the post you quoted suggests one way to be a little more explicit about what you're doing vis-a-vis string formatting:
Python code:
            qry = "OBJECTID in ({})".format(','.join(oidstrlist))
build a comma-separated list of elements, then drop 'em between parens. it's the same result as the tuple approach, just expresses your intent more clearly in code, rather than indirectly indicating it by switching data structures.

holy gently caress dude

i changed it to work this way (though it needs to be "OBJECTID in ({0})" because python 2.6 (that's what arc10 supports

)) and it now takes 4 seconds to select 371000 features, instead of the hour and a half it took the original way

this owns, thanks!

# ? Jul 24, 2013 19:59

PleasingFungus: Oct 10, 2012; idiot asshole bitch who should fuck off

dur posted:

holy gently caress dude

i changed it to work this way (though it needs to be "OBJECTID in ({0})" because python 2.6 (that's what arc10 supports )) and it now takes 4 seconds to select 371000 features, instead of the hour and a half it took the original way

this owns, thanks!

and here I thought I was just sperging about Proper Usage! super glad I could help.

# ? Jul 24, 2013 22:54

PleasingFungus: Oct 10, 2012; idiot asshole bitch who should fuck off

MeruFM posted:

This is definitely the most complex a single list comprehension should be
code:
for user in [post.user() for post in thread if poo poo(post) is True]:
    user.ban()

I don't understand. why include the conditional check if it's always going to return True?

# ? Jul 24, 2013 22:55

double sulk: Jul 2, 2010

PleasingFungus posted:

I don't understand. why include the conditional check if it's always going to return True?

# ? Jul 24, 2013 22:58

dragon enthusiast: Jan 1, 2010

yospos a few months ago there was chatte about natural language unit test generators where you could go like

add(2,4) should equal 6
butts("piss") should throw PoopException

I don't remember the names of any of those generators and now I want to look at some of them and Google isn't helping

# ? Jul 25, 2013 02:18

Nomnom Cookie: Aug 30, 2009

unit tests is requirements with code inside

-- a thing dumb babby p-langers say

# ? Jul 25, 2013 02:33

JewKiller 3000: Nov 28, 2006; by Lowtax

but if your unit tests have code inside, who's to say that code does what you meant? you need unit tests for it

# ? Jul 25, 2013 02:34

uG: Apr 23, 2003; by Ralp

my unit tests are just generated boilerplate files, no code

# ? Jul 25, 2013 02:46

PleasingFungus: Oct 10, 2012; idiot asshole bitch who should fuck off

some day I will work in a company with a rich testing environment

that day is not today

# ? Jul 25, 2013 03:19

JewKiller 3000: Nov 28, 2006; by Lowtax

PleasingFungus posted:

some day I will work in a company with a rich testing environment

NOPE

# ? Jul 25, 2013 03:21

Bloody: Mar 3, 2013

uG posted:

my unit tests are just generated boilerplate files, no code

this except pretty much my whole project

# ? Jul 25, 2013 04:01

PleasingFungus: Oct 10, 2012; idiot asshole bitch who should fuck off

JewKiller 3000 posted:

NOPE

wait, you're the guy who claims that java/python/etc aren't "real programming languages" (as opposed to esoteric academic functional languages, aka, all functional languages)

your opinions are a very strange mix.

# ? Jul 25, 2013 05:24

JewKiller 3000: Nov 28, 2006; by Lowtax

java is a real programming language although its subtyping is probably undecidable and it needs better support for first-class functions. algebraic datatypes would be nice too. so basically scala

python is a joke

# ? Jul 25, 2013 05:29

Nomnom Cookie: Aug 30, 2009

The actual most important thing about a language is available libraries. This makes java/scala the best language for any purpose permitting a jvm

# ? Jul 25, 2013 05:44

Shaggar: Apr 26, 2006

PleasingFungus posted:

some day I will work in a company with a rich testing environment

that day is not today

# ? Jul 25, 2013 05:44

Shaggar: Apr 26, 2006

Nomnom Cookie posted:

The actual most important thing about a language is available libraries. This makes java/scala the best language for any purpose permitting a jvm

Most of the popular java libs have c# versions or standard library equivalents these days.

# ? Jul 25, 2013 05:46

JewKiller 3000: Nov 28, 2006; by Lowtax

c# is better than java but not better than f# :v:

# ? Jul 25, 2013 05:51

DONT THREAD ON ME: Oct 1, 2002; by Nyc_Tattoo; Floss Finder

ruby's active record/active support/active model libraries are so good i cant imagine ever needing anything else

# ? Jul 25, 2013 06:00

Nomnom Cookie: Aug 30, 2009

Shaggar posted:

Most of the popular java libs have c# versions or standard library equivalents these days.

Lord prevent me from encountering a problem the C# stdlib can solve

# ? Jul 25, 2013 06:00

Nomnom Cookie: Aug 30, 2009

chumpchous posted:

ruby's active record/active support/active model libraries are so good i cant imagine ever needing anything else

Wow rails has static typing? People really aren't kidding when they say rails programmers don't know ruby

# ? Jul 25, 2013 06:01

uG: Apr 23, 2003; by Ralp

chumpchous posted:

ruby's active record/active support/active model libraries are so good i cant imagine ever needing anything else

you still need C to do all the actual work for your ruby bindings if you want things to finish running in a timely fashion (probably not as you are using ruby)

# ? Jul 25, 2013 06:03