如何在列表中返回列表元素？

Question

So I essentially have a 2 and 1/2 dimensional matrix and I want to return an element from a list within a list.

def somefunc(x):
    # What I want to do is return the max element within a matrix based on l[:][1]
    return j

# example
l = [[[1,2,3],4],
    [[5,6,7],8],
    [[9,1,2],3]]

>>>somefunc(l)
[[5,6,7],8]

Answer 1

Use key parameter in max() function.

def somefunc(x):
    return max(x, key=lambda e: e[1])