python - Django model field dependent on instance -

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i trying create model field dependent on instance (specifically instance of foreign key).

example:

class user(models.model):     name = models.charfield()     ...  class entry(models.model):     user = models.foreignkey(user)     file = models.filefield(upload_to=user.name)

as can see, want file "upload_to" parameter dependent on user. there easy way this?

upload_to may callable, such function, called obtain upload path, including filename.

this callable must able accept 2 arguments, , return unix-style path (with forward slashes) passed along storage system. 

def _upload_to(instance, filename):     return str(instance.user.name)  class entry(models.model):     user = models.foreignkey(user)     file = models.filefield(upload_to=_upload_to)

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