How to assign a local file to the FileField in Django?

Question

I was trying to assign a file from my disk to the FileField, but I have this error:

AttributeError: 'str' object has no attribute 'open'

My python code:

pdfImage = FileSaver()
pdfImage.myfile.save('new', open('mytest.pdf').read())

and my models.py

class FileSaver(models.Model):

    myfile = models.FileField(upload_to="files/")

    class Meta:
        managed=False

Thank you in advance for your help

score 51 · Accepted Answer · edited Feb 04 '19 at 09:41

51

Django uses it's own file type (with a sightly enhanced functionality). Anyway Django's file type works like a decorator, so you can simply wrap it around existing file objects to meet the needs of the Django API.

from django.core.files import File

local_file = open('mytest.pdf')
djangofile = File(local_file)
pdfImage.myfile.save('new', djangofile)
local_file.close()

You can of course decorate the file on the fly by writing the following (one line less):

pdfImage.myfile.save('new', File(local_file))

edited Feb 04 '19 at 09:41

pupeno

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answered Aug 17 '10 at 12:27

tux21b

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4

overwriting is probably a bad idea. Better to use file_ – Aaron McMillin Feb 22 '13 at 15:17
8

Just to explain the above comment (I was confused for a bit) Aaron is talking about the symbol `file` (i.e. the name of the variable) rather than the type of argument passed. – Joe Sep 10 '13 at 08:36
Remember to close both the python file object, _and_ the Django File object. – Rune Kaagaard Nov 14 '19 at 08:36
1

If you get a `UnicodeDecodeError`, try open the file in binary mode: `local_file = open("mytest.pdf", "rb")`. – nik_m Aug 20 '20 at 10:48
1

As the "file" variable was renamed to "local_file" in the answer, @AaronMcMillin ' s comment doesn't make sense anymore. – Alan Evangelista Jun 16 '21 at 14:06

score 2 · Answer 2 · answered Feb 11 '21 at 19:02

If you don't want to open the file, you can also move the file to the media folder and directly set myfile.name with the relative path to MEDIA_ROOT :

import os
os.rename('mytest.pdf', '/media/files/mytest.pdf')
pdfImage = FileSaver()
pdfImage.myfile.name = '/files/mytest.pdf'
pdfImage.save()

score 2 · Answer 3 · answered Sep 02 '21 at 23:46

if you are getting error like:

UnicodeDecodeError: 'utf-8' codec can't decode byte 0x89 in position...

then you have to open the file in binary mode: open("mytest.pdf", "rb")

full example:

from django.core.files import File

pdfImage = FileSaver()
pdfImage.myfile.save('new.pdf', File(open('mytest.pdf','rb')))

How to assign a local file to the FileField in Django?

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