bad operand type for abs(): 'str' in django
You are missing a cast somewhere in your code. 
Wherever in the code you're doing abs(somevar) you need to cast a string to an integer by doing abs(int(somevar)). More info if you post a stacktrace or pieces of code.
I am going through the beginning django ecommerce application for shopping cart app. I am getting the error as mentioned above while clicking the add to cart button.
I am getting the error at the line {{ cart_sutotal|currency}}