get such a number of elements as a percentage from a list [closed]

Question

I am trying to write a function that will allow me to extract a subset from a defined list. Note that the function returns two things:

• The original list with the subset removed S = S - S'
• the new list which contains only the subset S'

Example :

list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
new_list = get_purcentage(list, purcentage = 0.3)

# list should now be : 
# list =  [1, 2, 3, 4, 5, 6, 7]

# new_list should now be : 
# new_list =  [8, 9, 10]

I tried to use a library like train_test_split from sklearn.model_selection and it works as I want it to, but I would like to have my own code

Note: the order doesn't matter, the items can be taken randomly

Answer 1

self.object.save() keeps overwriting your object. You want to create separate db records from each line of your textarea input.

Better create a simple form forms.Form for data entry instead of ModelForm.

Then on the its form_valid, iterate through the lines and create objects. Each iteration should create a new object and save.

You need to get rid of the textarea field as well.

If its a lot of data, it’s better to use bulk create function for performance.

Answer 2

I found the solution after reading this https://stackoverflow.com/a/33027228/13152307 .

I should set the primary key to none at the beginning of each iteration.

for each_line in data_line_list:
    self.object.pk = None    #add this line
    each_line_list = each_line.split(",")
    self.object.part_number = each_line_list[0]
    self.object.length = each_line_list[1]
    self.object.weight = each_line_list[2]
    self.object.height = each_line_list[3]
    self.object.save()

I understand that it may not be a good way to do so, but at least it works now.