# Exception in random numbering node **URL:** \ **Category:** Lists-Logic\ **Created:** [November 18, 2017, 6:45pm UTC](https://forum.dynamobim.com/t/exception-in-random-numbering-node/16624 "2017-11-18T18:45:59Z")\ **Posts on this page:** 1\ **Showing post:** 17
**Author:** ![Yna\_Db](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/yna_db/32/30641_2.png) [@Yna\_Db](https://forum.dynamobim.com/u/Yna_Db)\ **Post date:** [November 20, 2017, 2:25pm UTC](https://forum.dynamobim.com/t/exception-in-random-numbering-node/16624/17 "2017-11-20T14:25:30Z")
A good explanation can be found in this post: > [@Revit API & python relations](https://forum.dynamobim.com/t/revit-api-python-relations/9188/2): > > Hi sajo We know it’s overwhelming, but you are more likely to get quick responses if you break these questions down into separate posts/subjects. In any case, I will try to touch on some of the points: What does the first four similar lines of every script do…? See comments below import clr # imports Common Language Runtime library .This will serve as a bridge between python and the .NET wold # See this: http://ironpython.net/documentation/dotnet/dotnet.html clr.AddReference('Proto… --- _[View the full topic](https://forum.dynamobim.com/t/exception-in-random-numbering-node/16624)._