Answer by Bharel for How can I partition (split up, divide) a list based on a...
Simple generator version, holds the least amount of values possible in memory and calls pred only once:from collections import dequefrom typing import Callable, TypeVar, Iterable_T = TypeVar('_T')def...
View ArticleAnswer by JustinFisher for How can I partition (split up, divide) a list...
This question has many answers already, but all seem inferior to my favorite approach to this problem, which iterates through and tests each item just once, and uses the speed of list-comprehension to...
View ArticleAnswer by double0darbo for How can I partition (split up, divide) a list...
I turned to numpy to solve this to limit lines and make into a simple function.I was able to get a conditional met, separating a list into two, using np.where to separate out a list. This works for...
View ArticleAnswer by ChaimG for How can I partition (split up, divide) a list based on a...
Clear and fastThis list comprehension is simple to read and fast. Exactly what the OP asked for.set_good_vals = set(good_vals) # Speed boost.good = [x for x in my_list if x in set_good_vals]bad = [x...
View ArticleAnswer by Ymareth for How can I partition (split up, divide) a list based on...
A generator based version, if you can put up with one or maybe two reversals of the original list.A setup...random.seed(1234)a = list(range(10))random.shuffle(a)a[2, 8, 3, 5, 6, 4, 9, 0, 1, 7]And the...
View ArticleAnswer by thehappycheese for How can I partition (split up, divide) a list...
The previous answers don't seem to satisfy all four of my obsessive compulsive ticks:Be as lazy as possible,Evaluate the original Iterable only onceEvaluate the predicate only once per itemProvide nice...
View ArticleAnswer by scp10011 for How can I partition (split up, divide) a list based on...
Use Boolean logic to assign data to two arrays>>> images, anims = [[i for i in files if t ^ (i[2].lower() in IMAGE_TYPES) ] for t in (0, 1)]>>> images[('file1.jpg', 33,...
View ArticleAnswer by Trylks for How can I partition (split up, divide) a list based on a...
You can do lazy functional programming in Python, like this:partition = lambda l, c: map( lambda iii: (i for ii in iii for i in ii), zip(*(([], [e]) if c(e) else ([e], []) for e in l)))Functional...
View ArticleAnswer by Phil B for How can I partition (split up, divide) a list based on a...
good.append(x) if x in goodvals else bad.append(x)This elegant and concise answer by @dansalmo showed up buried in the comments, so I'm just reposting it here as an answer so it can get the prominence...
View ArticleAnswer by Biga for How can I partition (split up, divide) a list based on a...
bad = []good = [x for x in mylist if x in goodvals or bad.append(x)]append returns None, so it works.
View ArticleAnswer by Shay for How can I partition (split up, divide) a list based on a...
Yet another answer, short but "evil" (for list-comprehension side effects).digits = list(range(10))odd = [x.pop(i) for i, x in enumerate(digits) if x % 2]>>> odd[1, 3, 5, 7, 9]>>>...
View ArticleAnswer by Chrisjan for How can I partition (split up, divide) a list based on...
images = [f for f in files if f[2].lower() in IMAGE_TYPES]anims = [f for f in files if f not in images]Nice when the condition is longer, such as in your example. The reader doesn't have to figure out...
View ArticleAnswer by ChaimG for How can I partition (split up, divide) a list based on a...
Elegant and FastInspired by DanSalmo's comment, here is a solution that is concise, elegant, and at the same time is one of the fastest solutions.good_set = set(goodvals)good, bad = [], []for item in...
View ArticleAnswer by David for How can I partition (split up, divide) a list based on a...
If the list is made of groups and intermittent separators, you can use:def split(items, p): groups = [[]] for i in items: if p(i): groups.append([]) groups[-1].append(i) return...
View ArticleAnswer by Pavel Ilchenko for How can I partition (split up, divide) a list...
For example, splitting list by even and oddarr = range(20)even, odd = reduce(lambda res, next: res[next % 2].append(next) or res, arr, ([], []))Or in general:def split(predicate, iterable): return...
View ArticleAnswer by kiran for How can I partition (split up, divide) a list based on a...
Not sure if this is a good approach but it can be done in this way as wellIMAGE_TYPES = ('.jpg','.jpeg','.gif','.bmp','.png')files = [ ('file1.jpg', 33L, '.jpg'), ('file2.avi', 999L, '.avi')]images,...
View ArticleAnswer by MSeifert for How can I partition (split up, divide) a list based on...
If you don't mind using an external library there two I know that nativly implement this operation:>>> files = [ ('file1.jpg', 33, '.jpg'), ('file2.avi', 999, '.avi')]>>> IMAGE_TYPES...
View ArticleAnswer by radeklat for How can I partition (split up, divide) a list based on...
Yet another solution to this problem. I needed a solution that is as fast as possible. That means only one iteration over the list and preferably O(1) for adding data to one of the resulting lists....
View ArticleAnswer by FunkySayu for How can I partition (split up, divide) a list based...
Sometimes, it looks like list comprehension is not the best thing to use !I made a little test based on the answer people gave to this topic, tested on a random generated list. Here is the generation...
View ArticleAnswer by Gecko for How can I partition (split up, divide) a list based on a...
I think a generalization of splitting a an iterable based on N conditions is handyfrom collections import OrderedDictdef partition(iterable,*conditions):'''Returns a list with the elements that satisfy...
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