numpy-equivalent of list.pop?

Question

Is there a numpy method which is equivalent to the builtin pop for python lists?

Popping obviously doesn't work on numpy arrays, and I want to avoid a list conversion.

Answer 1

There is no pop method for NumPy arrays, but you could just use basic slicing (which would be efficient since it returns a view, not a copy):

In [104]: y = np.arange(5); y Out[105]: array([0, 1, 2, 3, 4])  In [106]: last, y = y[-1], y[:-1]  In [107]: last, y Out[107]: (4, array([0, 1, 2, 3])) 

If there were a pop method it would return the last value in y and modify y.

Above,

last, y = y[-1], y[:-1] 

assigns the last value to the variable last and modifies y.

Answer 2

Here is one example using numpy.delete():

import numpy as np arr = np.array([[1,2,3,4], [5,6,7,8], [9,10,11,12]]) print(arr) #  array([[ 1,  2,  3,  4], #         [ 5,  6,  7,  8], #         [ 9, 10, 11, 12]]) arr = np.delete(arr, 1, 0) print(arr) # array([[ 1,  2,  3,  4], #        [ 9, 10, 11, 12]])