How to replicate array to specific length array

Question

I want replicate a small array to specific length array

Example:

var = [22,33,44,55] # ==> len(var) = 4
n = 13

The new array tha

Answer 1

There are better ways to replicate the array, for example you could simply use np.resize:

Return a new array with the specified shape.

If the new array is larger than the original array, then the new array is filled with repeated copies of a. [...]

>>> import numpy as np
>>> var = [22,33,44,55]
>>> n = 13
>>> np.resize(var, n)
array([22, 33, 44, 55, 22, 33, 44, 55, 22, 33, 44, 55, 22])

Answer 2

First of all, you don't get an error, but a warning, that var_new[di] = var is deprecated if var_new[di] has dimensions that do not match var.

Second, the error message tells what to do: use

var_new[di].flat = var

and you do not get a warning any more and it is guaranteed to work.

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Another, easy way to do this if numpy is not needed is to just use itertools:

>>> import itertools as it
>>> var = [22, 33, 44, 55]
>>> list(it.islice(it.cycle(var), 13))
[22, 33, 44, 55, 22, 33, 44, 55, 22, 33, 44, 55, 22]

Answer 3

Copy the array (called lists in python) with [:] because they are mutable. The python short cut is then just to multiply the copy and add one more element.

>>> var = [22, 33, 44, 55]
>>> n = 3
>>> newlist = var[:]*n + var[:1]

gives the 13 elements you want.

Answer 4

var = [22,33,44,55]
n = 13

Repeating a list (or any other iterable) can be done without numpy, using itertools's cycle() and islice() functions

from itertools import cycle, islice
var_new = list(islice(cycle(var),0,n)