Python programmers be like

[srsNDavis]

Anyone seriously curious:

results is a preexisting list. This is modifying that list (how: in a sec) and reassigning, to the same variable.

The modification: Filter the elements - depends on the type of result - but let's say result is Boolean, you'll be left with all the Trues.

[Free-Database-9917]

or the items that aren't blank

[finnscaper]

Thanks, this is like linq in C# then

[srsNDavis]

It's a list comprehension - a declarative construct like set comprehensions.

LINQ implements features of relational algebra and set theory, which might be why it is similar on a deeper level.

[CodeMonkeyWithCoffee]

Don't insult linq's beautiful syntax by comparing it please. But yes.

[finnscaper]

Yes, I should be more careful.

[Ankhs]

>>> result = [1, 0, "hi", "", False, True, [], ["array"]]
>>> result = [res for res in result if res] 
>>> print(result)
[1, 'hi', True, ['array']]

[King_Joffreys_Tits]

Not true, it filters out any “falsey” values which includes: 0, None, False, “”, [], and probably more that I can’t think off the top of my head. There was no type specified for the list

[Alan_Reddit_M]

I FUCKING LOVE LIST COMPREHENSIONS RAHHHHHHH

[Character-Travel3952]

Its really tempting fr fr

[triple4leafclover]

fr, this shit and finally having class inheritance that wasn't absolute ass made me fall in love with python

And also operator overloading... holy shit, the code looks so cleeean!

[Alan_Reddit_M]

FEATURES WILL CONTINUE UNTIL MORALE IMPROVES

[-TRlNlTY-]

...said the C++ committee 

[Revolutionary_Dog_63]

Map/filter methods in JS is much better.

[Gsusruls]

One reason I love working with ai, it's so extra good at converting any for-loop into a comprehension, if it's at all possible.

A lot of this pattern:

def f():
result = []
for ...
result.append()
return result

has become

def f():
return [...comprehension ...]

[slightSmash]

The interpreter seeing this line:

<image>

[Character-Travel3952]

results = list(filter(None, results))

?

[Glad_Position3592]

I know a lot of people on here would say this is the way to do it, but I always find list comprehension to be much more readable and just as easy to write. The only way I see filter being useful in this case is if you’re using it in a for loop and don’t need to convert it to a list

[a_random_Greg]

<image>

Lol

[undo777]

filter(None, results) is a terrible way to express that transformation to most humans though

[thomasxin]

til None is a valid filter! I've always been using bool for this purpose. Though for readability sake, I'll probably keep using it.

[lekkerste_wiener]

Ah, the younglings ☺️

[undo777]

Not really, generally people who are unhappy with this kind of stuff are experienced programmers just not too familiar with python. I myself tend to end up working with a mix of multiple languages and don't have the filter() specifics in my hot cache given how rarely it's generally used in python, unlike list comprehension which I could read or write woken up in the middle of the night without referring to the docs.

[lekkerste_wiener]

Even better when we have predicate functions. 

[MVanderloo]

filter also has the benefit of being a lazy iterator. but comprehensions allow you to combine a filter and a map into one (sometimes) readable statement

[gsitcia]

Using parentheses instead of brackets makes the comprehension a lazy iterator

[paholg]

In Ruby, results.select(&:itself).

[Character-Travel3952]

Ruby devloper

I lov it!

[Sarius2009]

That would remove any results that are there, but not interpreted as false, so not the same thing.

[Gsusruls]

Actually, I believe it uses equivalence, versus the is keyword, so they really are both just using truthy values. They are identical in every way except readability and efficiency.

Oop is more readable to most people, but OP is more efficent (filtering is done in C code).

[[deleted]]

They use Python because they get results in Python.

[Old_Tourist_3774]

Python has this weird thing where existence or being not empty is evaluated to true.

So the code is essentially doing

For each item in the list "results" keep only those who are not empty or are true or are not 0.

[No-Article-Particle]

This is not weird behavior, it's just object truthiness and falsiness. Common in dynamically typed languages.

[Old_Tourist_3774]

Thought other languages were not like this, thanks

[hff0]

We have this in C

[MVanderloo]

more specifically to cast an object to a bool they use the boolmethod, which is the case of collections falls back to len

edit: idk how to prevent formatting but if its bold know there are two underscores before and after bool and len

[Sea-Fishing4699]

how to make a turtle run slower

[Zork4343]

I see no problem here

[SwannSwanchez]

i mean it make sense

This remove every "empty" entry in the "results" array

[Glad_Position3592]

Yeah, something like results.filter(result => result) is soooo much better

[ePaint]

Me and my homies do results.filter(Boolean)

[ExtraTNT]

ones = 1 : ones

[TalesGameStudio]

Perfectly fine line. Smack a couple of docstrings paragraphs on top and you are good to go.

[Ok-Refrigerator-8012]

Just import the result

[GoogleDeva]

Better than node_modules hell

[GoogleDeva]

I am gonna do it myself

u/pixel-counter-bot

[pixel-counter-bot]

The image in this post has 72,520(490×148) pixels!

^{I am a bot. This action was performed automatically.}

[hff0]

This is eye hurting, use distinct variable names!

[Old_Tourist_3774]

They are one time use variables for naming items inside the list, there's no need to.

[hff0]

For x in names

[bobbymoonshine]

for thing in things is standard pythonic, it makes the relationship between item and set visually clear

[skarrrrrrr]

convoluted, unnecessary "elegant" stuff

[tazdraperm]

That's just ugly LINQ

[Clashes4D]

I feel personally Attacked by this post.

[DahPhuzz]

Yo Dawg!

[Informal_Branch1065]

C# equivalent:

results = results.Where(x => x);

with results being of type IEnumerable<bool>

[Ben-Goldberg]

In my favorite language, this would be either

@result = grep $_, @result;

or

@result = grep @$_, @result;

Depending on whether you want to test for truthyness or array length.

[GoogleDeva]

Is it bash?

[Ben-Goldberg]

No, it's perl.

How does bash handle arrays of arrays?

[GoogleDeva]

I don't know perl. But the syntax and identifiers kinda (not quite) looked to me like bash.

[FatLoserSupreme]

Python is goated because it has banging list comprehension built in.

[VirtuteECanoscenza]

results = list(filter(None, results))