在post_save信号中使用Python深度复制吗？

Question

The following code is in a Django signal and when the number of copies is '2', the following code creates 80+ copies and then crashes...What's wrong?

def internal_signal(sender, instance, signal, created, *args, **kwargs):
       for i in range(instance.number_of_copies):
            item_copy = deepcopy(instance)
            item_copy.id = item_copy.id + 1
            item_copy.internal_barcode = "%s"%(item_copy.item_location.location_code)
            item_copy.save()

post_save.connect(internal_signal, sender=Inventory)

Thanks.

Edit: Duh! Found the issue, the above code was part of post_save operation of a Django signal, so every 'save' triggers another loop and then heap crash.

What is the best way to create 'n' objects and save it in Django programatically?

Answer 1

This is my test code,it performanced as expected . I think you should make a unit test to find where the problem is. Leave Django alone!

class T:
    def save(this):
        pass
from copy import deepcopy
from copy import copy
instance = T() 
instance.number_of_copies = 2
instance.id = 1 
instance.item_location=T()
instance.item_location.location_code = 2 
for i in range(instance.number_of_copies):
    item_copy = deepcopy(instance)
    item_copy.id = item_copy.id + 1 
    item_copy.internal_barcode = "%s"%(item_copy.item_location.location_code)
    item_copy.save()
    print " id,code:",item_copy.id,item_copy.internal_barcode