Python: filtering lists by indices

Question

In Python I have a list of elements aList and a list of indices myIndices. Is there any way I can retrieve all at once those items in aList

Answer 1

Indexing by lists can be done in numpy. Convert your base list to a numpy array and then apply another list as an index:

>>> from numpy import array
>>> array(aList)[myIndices]
array(['a', 'd', 'e'], 
  dtype='|S1')

If you need, convert back to a list at the end:

>>> from numpy import array
>>> a = array(aList)[myIndices]
>>> list(a)
['a', 'd', 'e']

In some cases this solution can be more convenient than list comprehension.