Initializing a list to a known number of elements in Python [duplicate] Initializing a list to a known number of elements in Python [duplicate] python python

Initializing a list to a known number of elements in Python [duplicate]


The first thing that comes to mind for me is:

verts = [None]*1000

But do you really need to preinitialize it?


Not quite sure why everyone is giving you a hard time for wanting to do this - there are several scenarios where you'd want a fixed size initialised list. And you've correctly deduced that arrays are sensible in these cases.

import arrayverts=array.array('i',(0,)*1000)

For the non-pythonistas, the (0,)*1000 term is creating a tuple containing 1000 zeros. The comma forces python to recognise (0) as a tuple, otherwise it would be evaluated as 0.

I've used a tuple instead of a list because they are generally have lower overhead.


One obvious and probably not efficient way is

verts = [0 for x in range(1000)]

Note that this can be extended to 2-dimension easily. For example, to get a 10x100 "array" you can do

verts = [[0 for x in range(100)] for y in range(10)]


matomo