Increment Last Id from String in python Django

Question

I am trying to generate an auto-increment number as an ID with Company Label. Company Labels will be changing for every user. So I cant use slicing here.

My ID is like TES-PRODUCT-01

TES is a company label PRODUCT is as it is name

But now I wish to change my last number when I am adding new product to TES-PRODUCT-02 and so on

Getting Error **can only concatenate str (not "int") to str**

Here is my code views.py

def add_new_stock(request):
stock_data=New_Stock_Entry.objects.all()
if not stock_data:
    latest_item_code="TES-PRODUCT-001"
else:
    latest_item_code = (New_Stock_Entry.objects.last()).item_code+1

get_tax_code=Tax_Settings.objects.values('name', 'tax_percentage','tax_id')

if request.method == 'POST':
    item = request.POST['item']
    hsn = request.POST['hsn']
    item_code=latest_item_code
    stock_in_date=request.POST['stock_in_date']
    quantity_in_hand=request.POST['quantity_in_hand']
    sales_price=request.POST['sales_price']
    item_description=request.POST['item_description']
    unit=request.POST['unit']
    tax_code = request.POST['tax_code']
    tax_obj = Tax_Settings.objects.get(tax_id=tax_code)
    item_creation_details = New_Stock_Entry.objects.create(item=item, hsn=hsn, item_code=item_code,stock_in_date=stock_in_date,quantity_in_hand=quantity_in_hand,sales_price=sales_price ,item_description=item_description, unit=unit, tax_code=tax_obj)
    item_creation_details.save()
    print("item_details",item_creation_details)
    return render(request,"inventory/add-stock.html")
return render(request,"inventory/add-stock.html",{'get_tax':get_tax_code,'latest_item_code':latest_item_code})

html

<input type="text" class="form-control" placeholder="TES-PRODUCT-{{latest_item_code}}" name="item_code">

How Can I increment my last number from string?

to remove the concatenation error you can cast int to str and then concat them, this might help : stackoverflow.com/questions/27771000/… — Abhishek
– Abhishek, Commented Jul 16, 2022 at 12:07

Joshua Edward · Accepted Answer · 2022-07-16 12:13:49Z

0

You can simply use "f-strings"

total_stock = New_Stock_Entry.objects.all().count() + 1
latest_item_code=f"TES-PRODUCT-{total_stock}"

answered Jul 16, 2022 at 12:13

Joshua Edward

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