In Python dynamo variable is not updated in the first loop iteration

[REDO79]

I've writen a python script inside dynamo which offset a circle inward with a given offset distance and in the same time create an arc of 12 m length in each offset circle then rotate them (created arcs) by overlapping till the remainder lenght is < 12m...my script works, but I get the first arc in each circle duplicated

This issue is due to a non updated variable (End_Angle) in the first loop iteration (see image below)

Remark: I posted my question in dynamobim forum here, but I didn't get a desired solution!!.. although I know that I can manipulate my lists and remove each duplicated arc, but I want find a real solution which allows me to update that variable and fix this issue.
Please check my code below for more details:
https://github.com/REDO79/arc.git

Thanks.