# List - match wall lengths by name **URL:** \ **Category:** Revit\ **Tags:** dynamo\ **Created:** [October 14, 2021, 2:11pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307 "2021-10-14T14:11:11Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![YBMCarlos](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/ybmcarlos/32/125321_2.png) [@YBMCarlos](https://forum.dynamobim.com/u/YBMCarlos)\ **Post date:** [October 14, 2021, 2:11pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/1 "2021-10-14T14:11:11Z")
Hello everyone, was wondering if i could match these two lists that I have here. I have wall names & wall lengths but was wondering if I could combine these lists so that the wall name matches with the wall length and vice versa. - Wanted to know if I could separate them by level? not sure if that’s possible. Any feedback will be greatly appreciated, thanks! ![help#1](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/f/6/f69319abe41976510e4eb89efcd519ec0b5543a1.png) ---
**Author:** ![aaronrumple](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/aaronrumple/32/195292_2.png) [@aaronrumple](https://forum.dynamobim.com/u/aaronrumple)\ **Post date:** [October 14, 2021, 3:25pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/2 "2021-10-14T15:25:09Z")
Combine the two list with - List \> Transpose You would need to pull the level info and add that to the combined list or filter ahead of time. (I’d do it after.) ---
**Author:** ![viktor\_kuzev](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/viktor_kuzev/32/48254_2.png) [@viktor\_kuzev](https://forum.dynamobim.com/u/viktor_kuzev)\ **Post date:** [October 14, 2021, 4:31pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/3 "2021-10-14T16:31:17Z")
They are already in separate sublists for each level the way you have taken them: ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/c/1/c1bfc35af075cc68ba99017a0a3d417e36c5721a.png) This is representing the level. ---
**Author:** ![YBMCarlos](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/ybmcarlos/32/125321_2.png) [@YBMCarlos](https://forum.dynamobim.com/u/YBMCarlos)\ **Post date:** [October 14, 2021, 8:33pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/4 "2021-10-14T20:33:56Z")
Oh yea i did see that, went over my head a bit. Is there a way i could combine all the data to match each other? I guess maybe even make an excel sheet exporting level, wall type, and length? ---
**Author:** ![solamour](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/solamour/32/153516_2.png) [@solamour](https://forum.dynamobim.com/u/solamour)\ **Post date:** [October 14, 2021, 8:49pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/5 "2021-10-14T20:49:46Z")
You can try the **List.GroupByKey** node 🙂 I created a proxy of your graph (Don’t have the Excel file), but you can switch out my entire graph after the `All Elements of Category` into your graph after your `Select.ByCategoryAndLevel` node. ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/2/e/2ef989270136725e71b32a6a30bb98926619b7b4.png) ---
**Author:** ![YBMCarlos](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/ybmcarlos/32/125321_2.png) [@YBMCarlos](https://forum.dynamobim.com/u/YBMCarlos)\ **Post date:** [October 25, 2021, 4:48pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/6 "2021-10-25T16:48:54Z")
Sorry for the late reply, I haven’t touched the script for a bit. I’ve just tried this out, maybe I’m not doing it correctly but its giving me the “dereferencing a non-pointer” error. ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/1/7/17fee070472c12f534a71a86af8dcd0c4d26f541.png) ---
**Author:** ![Nick\_Boyts](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/nick_boyts/32/76313_2.png) [@Nick\_Boyts](https://forum.dynamobim.com/u/Nick_Boyts)\ **Post date:** [October 25, 2021, 5:17pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/7 "2021-10-25T17:17:33Z")
You might have a null or empty somewhere in that list, but you also can’t use `GroupByKey` on sublists. You’ll need to apply (@L2) list levels to have it sort each sublist individually. ---
**Author:** ![YBMCarlos](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/ybmcarlos/32/125321_2.png) [@YBMCarlos](https://forum.dynamobim.com/u/YBMCarlos)\ **Post date:** [October 25, 2021, 5:29pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/8 "2021-10-25T17:29:16Z")
Hey Nick, thanks for the reply! I actually realized I had an issue with the “parametername” I wanted to get the length so ive changed it. It seems like now im getting the proper information I’ve wanted by using the @L2 function. Let me know if it looks correct to you, It looks like its matching to me but I need a better set of eyes on it. Thanks. ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/f/e/fe66a3558a1fef07bb556d7cb648d04d33625b06.png) ---
**Author:** ![Nick\_Boyts](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/nick_boyts/32/76313_2.png) [@Nick\_Boyts](https://forum.dynamobim.com/u/Nick_Boyts)\ **Post date:** [October 25, 2021, 5:33pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/9 "2021-10-25T17:33:32Z")
Can’t say for sure without seeing all of the outputs, but that should be the correct setup. ---
**Author:** ![YBMCarlos](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/ybmcarlos/32/125321_2.png) [@YBMCarlos](https://forum.dynamobim.com/u/YBMCarlos)\ **Post date:** [October 25, 2021, 5:38pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/10 "2021-10-25T17:38:15Z")
Thanks Nick! I have another problem haha. Not sure if I should start another topic for this. But now that I have that information. Is there anyway I can export that to some list that can be a bit easier to read. I’m trying to export it to excel (im sure this is probably the easiest way) but I want it to show it well. EX: Wall 1 Wall 2 10 12 Not sure if theres a way to do that? Again I can start another topic if needed. ---
**Author:** ![Nick\_Boyts](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/nick_boyts/32/76313_2.png) [@Nick\_Boyts](https://forum.dynamobim.com/u/Nick_Boyts)\ **Post date:** [October 25, 2021, 5:40pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/11 "2021-10-25T17:40:12Z")
Sounds like a new topic. Mark the solution for this one and start a new thread. You can always reference this thread in the new one if you need to. ---
**Author:** ![YBMCarlos](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/ybmcarlos/32/125321_2.png) [@YBMCarlos](https://forum.dynamobim.com/u/YBMCarlos)\ **Post date:** [October 25, 2021, 5:41pm UTC](https://forum.dynamobim.com/t/list-match-wall-lengths-by-name/69307/12 "2021-10-25T17:41:48Z")
Great! Thanks Nick!