Why the series_valid is not defined

[Deepti_Prasad]

go through the below comment to debug your codes

C4W1 Assignment compiling error resulting in 0 points

hi @edmos7 When you do now correction please make sure to get a fresh copy of assignment and only write codes between assigned markers ###START AND END CODE HERE### and making sure not to delete the already given instructions and do not add your own way of writing the codes. You suppose to only replace None placed between the Markers ###START AND END CODE HERE### without editing the already given instructions or part of codes already given to you when you first open the assignment notebook. By…