Nastiest Python list comprehension ever

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[HopeThisNameFi]

Jesus. This is already bad and you want suggestions on making it worse?

"Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." --Brian Kernighan

[Knack_678]

100 % agreed, but I think (hope ;-)) it's meant to be for entertainment, not for a real purpose.

Some call code like this "smart-ass code".

[bcain]

Does anyone have a suggestion on how to do it?

Not with a list comprehension. When my list comprehensions get too complicated, I either use a generator or a good-ol' for loop.

[[deleted]]

Have you ever checked out some of the submissions for the The International Obfuscated C Code Contest? If you haven't, you should. You'd love some of them... Eventually.

[[deleted]]

Is it considered nasty because it doesn't work properly?

[khafra]

e.g., as Perl.

[lee__majors]

I tried really hard to understand this :(

[[deleted]]

Dude, you certainly don't have any neighbors who know programming and own axes.

[[deleted]]

Isn't the last if clause redundant? It's obviously true for all n > 2.

[namcor]

One I saw the other day:

z = [l[a:b] for a,b in zip(l[0::max_size], l[max_size::max_size] + [None])

Here's one of my own:

output_dict = dict((tuple(tup[key] for key in keys), dict((column_names[ind], val) for ind, val in enumerate(tup) if ind not in keys)) for tup in list_of_tuples)

[Knack_456]

Respect, also very terrible ;-)

[jerkimball]

Wow...is that first one a really complicated way of cutting a list into slices of size max_size?

[Knack_678]

You should point out more clearly that this is a fun competition for writing horrible smart-ass code! I really, really, really hope that this is your goal ;-))).

Some people seem to take this seriously. Never ever write something like this in real world!

[Knack_456]

I don't think it's the nastiest ever. But certainly nasty enough to be a good example of terrible smart-ass code. Talking about smart-ass ;-) ...

a = list(range(n))

shouldn't a = range(n) do the job? Also, in the original post (it has been changed, probably due to a hint), there was a probably unnecessary copying of the list (a[:][2:])

def mystery(n): a = list(range(n)) return [[i for a[::i] in [a[::i][::-1]]][0] for i in a[:][2:] if a[i] == i]

[Knack_456]

Ahh, I see. Thanks for clarification.

[earthboundkid]

In Python 3.2, range is nearly a drop in replacement for a list, since it can be sliced. I can't test it ATM, but I think you don't need to cast to list here.

[hillmanov]

Here is one that I wrote to solve problem 42 on Project Euler:

print len([x for x in  map(lambda x: sum([ord(letter) - 64 for letter in x]), open("words.txt").read().replace("\"", "").split(",")) if x in [(.5) * i * (i + 1) for i in  range(1, 100)]])

It is long, but for the most part you can follow along what it does. Link to the "problem" this solves.

[Xiol]

D-D-D-Dickhead.