
Python: list of lists - Stack Overflow
The first, [:], is creating a slice (normally often used for getting just part of a list), which happens to contain the entire list, and thus is effectively a copy of the list. The second, list(), is using the actual …
slice - How slicing in Python works - Stack Overflow
The first way works for a list or a string; the second way only works for a list, because slice assignment isn't allowed for strings. Other than that I think the only difference is speed: it looks like it's a little …
What is the difference between List.of and Arrays.asList?
Oct 5, 2017 · @Sandy Chapman: List.of does return some ImmutableList type, its actual name is just a non-public implementation detail. If it was public and someone cast it to List again, where was the …
Array versus List<T>: When to use which? - Stack Overflow
Jan 12, 2009 · A List uses an internal array to handle its data, and automatically resizes the array when adding more elements to the List than its current capacity, which makes it more easy to use than an …
How to overcome TypeError: unhashable type: 'list'
A work around is create a custom_list type that inherits list with a method __hash__() then convert your list to use the custom_list datatype. still better to use built-in types.
.net - Creating a List of Lists in C# - Stack Overflow
Feb 25, 2015 · A list of lists would essentially represent a tree structure, where each branch would constitute the same type as its parent, and its leaf nodes would represent values.
Java Generics: List, List<Object>, List<?> - Stack Overflow
Jan 29, 2009 · List<String> L = new ArrayList<String>(); You should read that as "L is a kind of List that deals with String objects". When you start dealing with Factory classes, it is critical to deal with …
Sum a list of numbers in Python - Stack Overflow
Depending on how big your list is, several orders of magnitude faster. Also, it's a lot less code, and at least to me, it's easier to read. I'm trying to make a habit out of using numpy for all groups of …
How do I make a flat list out of a list of lists? - Stack Overflow
If your list of lists comes from a nested list comprehension, the problem can be solved more simply/directly by fixing the comprehension; please see How can I get a flat result from a list …
What is the difference between Python's list methods append and …
Oct 31, 2008 · What is the difference between the list methods append and extend? .append() adds its argument as a single element to the end of a list. The length of the list itself will increase by one. …