I'm trying to construct a list of list and do some operation on it. In Python I would do
In [7]: ll = [[1,2],[1,2,3],[7]] Say I want to sort them by the length of the list, many function accepts a `key` parameter. In this case I want the `key` to be `len`. In [8]: max(ll, key=len) Out[8]: [1, 2, 3] In [9]: sorted(ll, key=len) Out[9]: [[7], [1, 2], [1, 2, 3]] In Julia, if I enter the literal [[1,2],[1,2,3],[7]], then are join to together into a long list. Through many trial and error I found a way by ll = (Array)[[1,2],[1,2,3],[7]] What is the proper way to construct a list of list? Secondly, Julia's sort support a `by` parameter that does what `key` do in Python. But there is no equivalent in `maximum`. What is the recommended way to find the longest list in the data structure? Wai Yip
