How can I make the 1st element of list of lists to match the order of elements in another list? For example:
list1 = [3, 7, 1, 10, 4]
list2 = [[1,0],[3,2],[4,11],[7,9],[10,1]]
newlist = [[3,2],[7,9],[1,0],[10,1],[4,11]]
CodePudding user response：
You can use list.index:
list1 = [3, 7, 1, 10, 4]
list2 = [[1, 0], [3, 2], [4, 11], [7, 9], [10, 1]]
newlist = sorted(list2, key=lambda l: list1.index(l[0]))
print(newlist)
Prints:
[[3, 2], [7, 9], [1, 0], [10, 1], [4, 11]]
If the lists are large, I'd suggest to create a mapping from list1 and use that in the sorting key function:
m = {v: i for i, v in enumerate(list1)}
newlist = sorted(list2, key=lambda l: m[l[0]])
print(newlist)
CodePudding user response：
If the firsts in the second list are always a permutation of the first list (i.e., if that's not a misleading example):
firsts = next(zip(*list2))
first2full = dict(zip(firsts, list2))
newlist = [*map(first2full.get, list1)]