Asked By – Greg
Here’s my model. What I want to do is generate a new file and overwrite the existing one whenever a model instance is saved:
class Kitten(models.Model): claw_size = ... license_file = models.FileField(blank=True, upload_to='license') def save(self, *args, **kwargs): #Generate a new license file overwriting any previous version #and update file path self.license_file = ??? super(Request,self).save(*args, **kwargs)
I see lots of documentation about how to upload a file. But how do I generate a file, assign it to a model field and have Django store it in the right place?
Now we will see solution for issue: Django – how to create a file and save it to a model’s FileField?
Basically, a field declared as a
FileField, when accessed, gives you an instance of class
FieldFile, which gives you several methods to interact with the underlying file. So, what you need to do is:
new_name is the filename you wish assigned and
new_contents is the content of the file. Note that
new_contents must be an instance of either
django.core.files.base.ContentFile (see given links to manual for the details).
The two choices boil down to:
from django.core.files.base import ContentFile, File # Using File with open('/path/to/file') as f: self.license_file.save(new_name, File(f)) # Using ContentFile self.license_file.save(new_name, ContentFile('A string with the file content'))