v[-1] is the last element of a list or tuple. v[-2] is the second last. The syntax where you're doing v[a:b:c], is known as slice notation. a is the start position, b is the end position, and c is the increment. a and b default to the start and end. c defaults to 1, so... v[::] refers to all elements from start to end. Useful for copying whole content somewhere, as distinct from assigning the list to a new variable. v[::2] refers to every second element v[::-1] is all the element in reverse. v[::-2] is every second element in reverse. v[5:] is all elements from 5 to the end. v[:5] is all elements from the start to < 5, so v[:5] and v[5:] do not overlap. More on reddit.com

Let us step back a little. Before understanding your example, try to grok the example below for i in range(0, 3): print(i) which results in: 0 1 2 And the example below my_list = [42, 6, 2024] for i in range(0, 3): print(i, my_list[i]) Which results in: 0 42 1 6 2 2024 Are those clear to ya? Thanks! More on reddit.com

Sorry if this question has an easy answer - I couldn't find one, but I might be using the wrong search terms. From what I understand about arrays… More on reddit.com

I'm working through the lessons on indexing Indexing into lists, you mean? Let's talk a little bit about collections. Collections are values that act as containers for other values. Python has several different collection types - dictionaries, lists, sets, strings, and tuples are built-in to the language, and then there's a wealth of other collections types in the standard library and in other third-party libraries - and they have different properties that make them useful for different things. The properties of strings, you likely already have some idea of - you've probably never thought of it as a collection before, but it is: it's a collection of characters. The key differences among collection types are how things go in to the collection and how things come out. The decision you're making when you're deciding which collection type to use is about how you want to add items and how you want to retrieve them. If the solution to your problem feels like "look up a value based on an association with another value", then the dictionary type is what you want to use. If the solution to your problem feels like "add items sequentially, then retrieve them sequentially in the same order" then a list is probably what you want. If the solution to your problem feels like "this collection, once created, shouldn't be able to change" then you're looking at a tuple. If the solution feels like "a collection that's like a bucket, but with no duplicate items" then you're looking at a set. Indexing is part of how these different types promise to operate - something we call their type guarantee, or more commonly, their interface. Those are just words that mean "these types promise to operate in such-and-such a way, but you don't need to know how it works." The reason they expose an interface, and not a promise of implementation, is that the developers of Python want the freedom to change how they implement the promise, as new thinking and new technologies become available. Indexing is part of that promise - lists make a promise that you can retrieve elements according to their displacement from the beginning of the list (that's why lists are indexed starting with 0; the first item of the list is 0 items away from the beginning.) Dictionaries make a promise that you can look up a value from its key and not from the order of insertion, like in a list. In fact dictionaries don't make any promises about the order of their elements. More on reddit.com