In Python, how do I index a list with another list?

Question

I would like to index a list with another list like this

L = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']
Idx = [0, 3, 7]
T = L[ Idx ]

and T should end up being a list containing ['a', 'd', 'h'].

Is there a better way than

T = []
for i in Idx:
    T.append(L[i])

print T
# Gives result ['a', 'd', 'h']

Answer 1

T = [L[i] for i in Idx]

Answer 2

T = map(lambda i: L[i], Idx)

Answer 3

If you are using numpy, you can perform extended slicing like that:

>>> import numpy
>>> a=numpy.array(['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'])
>>> Idx = [0, 3, 7]
>>> a[Idx]
array(['a', 'd', 'h'], 
      dtype='|S1')

...and is probably much faster (if performance is enough of a concern to to bother with the numpy import)