Increment a mixed list of alphanumeric strings

Revit
1

So I have a list that can contain numbers and letters which are strings. On each routine this list needs to be incremented by 1, Example 1-2, 47-48, A-B and G-H. I can get it work by turning strings to numbers, +1 them in a code block then convert back to a string to populate the parameter. I can’t figure out how to do this with letters.
Has anyone come across something like this before?

2

A bit of googling brought me this. Maybe take a look at it and give it a shot.

3

Hello try this Python script

lst_toIncr = IN[0] #input value must be a string's list digit or alpha
out = []
for val in lst_toIncr:
	if val.isdigit():
		out.append(str(int(val) + 1))
	else:
		out.append(chr(ord(val) + 1))

OUT = out
3 Likes
4

increment
increment970×292 11.8 KB

List.IndexOf("A".."Z",a) == -1 ? String.ToNumber(a) + 1 : List.GetItemAtIndex(List.AddItemToEnd("A","A".."Z") , List.IndexOf("A".."Z",a) + 1);

2 Likes
5

Might be a bit faster to avoid the lookups, which will also help with mixed cases:

image
image1050×395 43.6 KB 

vals =
   String.ToNumber(a)==null?
      DSCore.List.LastItem((a..#2..1)<1L>):
      String.ToNumber(a)+1;
5 Likes
6

Cheers for that, this worked for what I need.

1 Like
7

Cheers again Jacob, this works on the newer version of Dynamo but this script sometimes has to work on Dynamo 1.3. Ill use this on projects post 2018.

1 Like
8

Ah, the horrors of the old versions. 2017 and up should support 2.0.4 though which might save you some coding time and package management and calculation times. Worth a consideration, but glad you’re sorted out either way. :slight_smile: