The colon, :, is what tells Python you're giving it a slice and not a regular index. That's why the idiomatic way of making a shallow copy of lists in Python 2 is

Oct 12, 2010 · The index or slice is passed to the methods as a single argument, and the way Python does this is by converting the slice notation, (1:10:2, in this case) to a slice object: slice(1,10,2).

Python interpreter is smart enough to convert a slice of range into another range. This is an optimization, ranges are generators. They are dynamic, i.e. they don't hold all the elements in the memory at once. …

Jul 19, 2015 · Whenever some other code uses slice notation on your an instance of your class Python will call your __getitem__ method with a slice object. (Older versions of Python used a __getslice__ …

To my understanding, slice means lst[start:end], and including start, excluding end. So how would I go about finding the "rest" of a list starting from an element n?

Aug 10, 2010 · 22 When slicing in Python the third parameter is the step. As others mentioned, see Extended Slices for a nice overview. With this knowledge, [::3] just means that you have not …

May 13, 2012 · Given a list a = range(10) You can slice it using statements such as a[1] a[2:4] However, I want to do this based on a variable set elsewhere in the code. I can easily do this for the first one ...

Here’s a useful invariant of slice operations: s[:i] + s[i:] equals s. For non-negative indices, the length of a slice is the difference of the indices, if both are within bounds. For example, the length of word[1:3] …

Feb 27, 2023 · Python's slicing also doesn't support 2D/multi-dimensional slicing for lists. The expected output for slicing a multi-dimensional list can be tricky. For example, If you want the third column …

Aug 31, 2012 · 45 Python 3 only answer (that doesn't use slicing or throw away the rest of the list, but might be good enough anyway) is use unpacking generalizations to get first and last separate from …