Here is my code
a = [10,11,12]
index = [0,2]
print(a[index])
I expect 10,12 as output, but get error:
TypeError: list indices must be integers, not list
Is is possible to achive something like this in python? I know I can do it with list comprehension, but want something simpler. The problem looks so pythonic.
What's wrong with list comprehensions?
In [1]: a = [10, 11, 12]
In [2]: indices = [0, 2]
In [3]: [a[i] for i in indices]
Out[3]: [10, 12]
You can use operator.itemgetter:
In [1]: from operator import itemgetter
In [2]: a = [10, 11, 12]
In [3]: index = [0, 2]
In [4]: itemgetter(*index)(a)
Out[4]: (10, 12)
If you want special semantics, you can create a list subclass:
class PickList(list):
def __getitem__(self, key):
return PickList([super(PickList, self).__getitem__(k) for k in key])
a = PickList([10,11,12])
index = [0, 2]
print a[index]
