在Python中的多个位置建立索引列表？

Question

Say I have two lists A which has 10 elements, and I want to assign the list B = [x1, y1] to values in A. If the values are sequential, it is straightforward eg A[1:3] = B . But what if my indices are non-sequential? In MATLAB I can do A([3 10]) = B; , is there an equivalently clean Python solution? The for loop to do this is straightforward, but I am wondering if I am missing something more "Pythonic".

Answer 1

Slightly more verbose, but you can use tuple unpacking to assign to new indices:

>>> x = range(1, 11)
>>> x[3], x[7] = 99, 999
>>> x
[1, 2, 3, 99, 5, 6, 7, 999, 9, 10]

Answer 2

Whenever I try to emulate some Matlab functionality in Python I use numpy. Using a numpy array instead of a python list allows to you get the functionality you are looking for with almost the same syntax as Matlab:

In [1]: import numpy as np

In [2]: a = np.arange(10)

In [3]: b = [200, 300]

In [4]: a[[2, 9]] = b

In [5]: a
Out[5]: array([  0,   1, 200,   3,   4,   5,   6,   7,   8, 300])