Python : How to reverse the order of sublist in a list?

Question

I have a list which is made up of nested lists. I want to rearrange the order of sublists. I tried using the list.reverse() method, however it reverses the elements of the sublist. I want to reverse just the order of sublist rather than the elements.

Input : [['25', '9', 'BID', 'toaster_1', '17.00'], ['26', '11', 'BID', 'toaster_1', '17.00']]
Expected Output : [['26', '11', 'BID', 'toaster_1', '17.00'],['25', '9', 'BID', 'toaster_1', '17.00']]

I tried this code, entry = entry[::-1] The output I got was : ['17.00', 'toaster_1', 'BID', '9', '25'] ['17.00', 'toaster_1', 'BID', '11', '26'] — user6662097, Aug 16 '20 at 14:04

score 3 · Accepted Answer · answered Aug 16 '20 at 14:09

3

initial_list=[['25', '9', 'BID', 'toaster_1', '17.00'], ['26', '11', 'BID', 'toaster_1', '17.00']]
modified_list=initial_list[::-1] #reverse the list
print(modified_list)

The 2nd line in the code reverse the list.From index value -1

answered Aug 16 '20 at 14:09

Smiley Face

86
5

That just looks like an inefficient unnecessary duplication. – superb rain Aug 16 '20 at 14:15

score 0 · Answer 2 · answered Aug 16 '20 at 14:05

0

I used array.reverse() and it worked as you wanted.

The test

Output: [['26', '11', 'BID', 'toaster_1', '17.00'], ['25', '9', 'BID', 'toaster_1', '17.00']]

answered Aug 16 '20 at 14:05

deltastar

45
1
10

maybe because I am running this inside a for loop, does it make any difference? let me try it outside for loop – user6662097 Aug 16 '20 at 14:10
@user6662097 Yes it makes a difference. – deltastar Aug 16 '20 at 14:11
@user6662097 Sounds like you maybe shouldn't reverse the list at all, but just iterate it in reverse? – superb rain Aug 16 '20 at 14:15
Hi, how to iterate a list in reverse? – user6662097 Aug 16 '20 at 14:27
@user6662097 Are you talking to me? You didn't address=notify me. `for sublist in reversed(mylist): ...`. – superb rain Aug 16 '20 at 15:24

Python : How to reverse the order of sublist in a list?

2 Answers2