How to insert multiple elements into a list?

Question

In JavaScript, I can use splice to insert an array of multiple elements in to an array: myArray.splice(insertIndex, removeNElements, ...insertThese).

But I can't seem to find a way to do something similar in Python without having concat lists. Is there such a way? (There is already a Q&A about inserting single items, rather than multiple.)

For example myList = [1, 2, 3] and I want to insert otherList = [4, 5, 6] by calling myList.someMethod(1, otherList) to get [1, 4, 5, 6, 2, 3]

Answer 1

To extend a list, you just use list.extend. To insert elements from any iterable at an index, you can use slice assignment...

>>> a = list(range(10))
>>> a
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> a[5:5] = range(10, 13)
>>> a
[0, 1, 2, 3, 4, 10, 11, 12, 5, 6, 7, 8, 9]

Answer 2

Python lists do not have such a method. Here is helper function that takes two lists and places the second list into the first list at the specified position:

def insert_position(position, list1, list2):
    return list1[:position] + list2 + list1[position:]

Answer 3

I'm not certain this question is still being followed but I recently wrote a short code that resembles what is being asked here. I was writing an interactive script to perform some analyses so I had a series of inputs serving to read in certain columns from a CSV:

X = input('X COLUMN NAME?:\n')
Y = input('Y COLUMN NAME?:\n')
Z = input('Z COLUMN NAME?:\n')
cols = [X,Y,Z]

Then, I brought the for-loop into 1 line to read into the desired index position:

[cols.insert(len(cols),x) for x in input('ENTER COLUMN NAMES (COMMA SEPARATED):\n').split(', ')]

This may not necessarily be as concise as it could be (I would love to know what might work even better!) but this might clean some of the code up.