Where do I put methods that perform create_if_missing or update_if_exists function in django?

In what location should I place methods that perform:

• Create this row if it is missing
• Update the row if it exists

for a django model ?

Additionally since I am using the default transaction scheme of django, this migh开发者_JAVA百科t introduce race conditions. How do I prevent that ?

Django has this built-in: get_or_create.

The answer is get_or_create.

I suppose it is obligatory to link to their docs as well.