python - What does list [x::y] do? - Stack Overflow
Jan 27, 2012 · list[a:b:c], a is the starting index, b is the ending index and c is the optional step size. This will give you a list starting at index a (inclusive) and ending at index b (exclusive) picking elements at …
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 …
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 …
What is the difference between list [1] and list [1:] in Python?
Oct 5, 2012 · By using a : colon in the list index, you are asking for a slice, which is always another list. In Python you can assign values to both an individual item in a list, and to a slice of the list.
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 …
What is the difference between list and list [:] in python?
Nov 2, 2010 · When reading, list is a reference to the original list, and list[:] shallow-copies the list. When assigning, list (re)binds the name and list[:] slice-assigns, replacing what was previously in the list. …
How do I convert all of the items in a list to floats? [duplicate]
How can I collect the results of a repeated calculation in a list, dictionary etc. (or make a copy of a list with each element modified)? (3 answers)
python - Access item in a list of lists - Stack Overflow
Jul 19, 2014 · You can access the elements in a list-of-lists by first specifying which list you're interested in and then specifying which element of that list you want. For example, 17 is element 2 in list 0, …
How do I subtract one list from another? - Stack Overflow
That's pretty much built into the nature of sets.** If you're trying to, e.g., subtract a list of dicts from another list of dicts, but the list to subtract is large, what do you do? If you can decorate your values …
c# - Checking for empty or null List<string> - Stack Overflow
Jun 24, 2014 · I have a List where sometimes it is empty or null. I want to be able to check if it contains any List-item and if not then add an object to the List. // I have a list, sometimes it doesn't have any