Download a file with Django - python

This might perhaps be a simple question, but I somehow just can not find the solution. Django offers a lot about uploading file, but how do I do to download a file.
Let's assume we have a button on HTML on uploads/something.txt as a file.
I tried with django.views.static.serve, however what this did it would open a file on webpage.
My question is simple: What is the best and most pythonic way for user of our website to download a file?

You need to read that file.
Serve it using HttpResponse along with proper content type.
Here's some sample code:
content = open("uploads/something.txt").read()
return HttpResponse(content, content_type='text/plain')
This should serve a text file.
But as you described, on some browser, it will not ask to download the file, rather, it would show it in the browser. If you want to show a download prompt, use this:
response = HttpResponse(open("uploads/something.txt", 'rb').read())
response['Content-Type'] = 'text/plain'
response['Content-Disposition'] = 'attachment; filename=DownloadedText.txt'
return response
However, please note that it might be a better idea to serve static contents or uploaded files via nginx or the reverse proxy of your choice. Sending large files through Django might not be the most optimum way of doing that.

import os
from django.conf import settings
from django.http import HttpResponse, Http404
def download(request, path):
file_path = os.path.join(settings.MEDIA_ROOT, path)
if os.path.exists(file_path):
with open(file_path, 'rb') as fh:
response = HttpResponse(fh.read(), content_type="application/vnd.ms-excel")
response['Content-Disposition'] = 'inline; filename=' + os.path.basename(file_path)
return response
raise Http404

Maybe a little late but here is my solution:
def render(self, value):
return format_html('<a href="/media/{0}" download>{0}</a>', value)

Related

Delete file when file download is complete on Python x Django [duplicate]

I'm using the following django/python code to stream a file to the browser:
wrapper = FileWrapper(file(path))
response = HttpResponse(wrapper, content_type='text/plain')
response['Content-Length'] = os.path.getsize(path)
return response
Is there a way to delete the file after the reponse is returned? Using a callback function or something?
I could just make a cron to delete all tmp files, but it would be neater if I could stream files and delete them as well from the same request.
You can use a NamedTemporaryFile:
from django.core.files.temp import NamedTemporaryFile
def send_file(request):
newfile = NamedTemporaryFile(suffix='.txt')
# save your data to newfile.name
wrapper = FileWrapper(newfile)
response = HttpResponse(wrapper, content_type=mime_type)
response['Content-Disposition'] = 'attachment; filename=%s' % os.path.basename(modelfile.name)
response['Content-Length'] = os.path.getsize(modelfile.name)
return response
temporary file should be deleted once the newfile object is evicted.
For future references:
I just had the case in which I couldn't use temp files for downloads.
But I still needed to delete them after it; so here is how I did it (I really didn't want to rely on cron jobs or celery or wossnames, its a very small system and I wanted it to stay that way).
def plug_cleaning_into_stream(stream, filename):
try:
closer = getattr(stream, 'close')
#define a new function that still uses the old one
def new_closer():
closer()
os.remove(filename)
#any cleaning you need added as well
#substitute it to the old close() function
setattr(stream, 'close', new_closer)
except:
raise
and then I just took the stream used for the response and plugged into it.
def send_file(request, filename):
with io.open(filename, 'rb') as ready_file:
plug_cleaning_into_stream(ready_file, filename)
response = HttpResponse(ready_file.read(), content_type='application/force-download')
# here all the rest of the heards settings
# ...
return response
I know this is quick and dirty but it works. I doubt it would be productive for a server with thousands of requests a second, but that's not my case here (max a few dozens a minute).
EDIT: Forgot to precise that I was dealing with very very big files that could not fit in memory during the download. So that is why I am using a BufferedReader (which is what is underneath io.open())
Mostly, we use periodic cron jobs for this.
Django already has one cron job to clean up lost sessions. And you're already running it, right?
See http://docs.djangoproject.com/en/dev/topics/http/sessions/#clearing-the-session-table
You want another command just like this one, in your application, that cleans up old files.
See this http://docs.djangoproject.com/en/dev/howto/custom-management-commands/
Also, you may not really be sending this file from Django. Sometimes you can get better performance by creating the file in a directory used by Apache and redirecting to a URL so the file can be served by Apache for you. Sometimes this is faster. It doesn't handle the cleanup any better, however.
One way would be to add a view to delete this file and call it from the client side using an asynchronous call (XMLHttpRequest). A variant of this would involve reporting back from the client on success so that the server can mark this file for deletion and have a periodic job clean it up.
This is just using the regular python approach (very simple example):
# something generates a file at filepath
from subprocess import Popen
# open file
with open(filepath, "rb") as fid:
filedata = fid.read()
# remove the file
p = Popen("rm %s" % filepath, shell=True)
# make response
response = HttpResponse(filedata, content-type="text/plain")
return response
Python 3.7 , Django 2.2.5
from tempfile import NamedTemporaryFile
from django.http import HttpResponse
with NamedTemporaryFile(suffix='.csv', mode='r+', encoding='utf8') as f:
f.write('\uFEFF') # BOM
f.write('sth you want')
# ref: https://docs.python.org/3/library/tempfile.html#examples
f.seek(0)
data=f.read()
response = HttpResponse(data, content_type="text/plain")
response['Content-Disposition'] = 'inline; filename=export.csv'

Serving pdf files by link, downloaded as pdf.html

Crated function to allow users download pdf files by link. Works fine, the only problem that what user save is .html. So all files are file.pdf.html.
def download(request,ticket_id):
ticket_path = str(Ticket.objects.get(id=ticket_id).upload)
with open('files/media/' + ticket_path, 'rb') as pdf:
response = HttpResponse(pdf.read())
response['content_type'] = 'application/pdf'
response['Content-Disposition'] = 'attachment;filename="file.pdf"'
return response
Why?
You should move content_type into HttpResponse(pdf.read(), content_type='application/pdf'), it's an attribute of HttpResponse

Django download image from ImageField

I'm working with Django 1.7 and Python 3.4.
I have a model like this one:
class ImageModel(models.Model):
image = models.ImageField(verbose_name='image', upload_to='uploaded_images/')
Now I want to download image which is saved in /static/uploaded_images/.
For example I have a link like this: www.example.com/image/download/1, where 1 is id of ImageModel object.
Now i have a view:
def download_image(request, image_id):
img = ImageModel.objects.get(id=image_id)
( what I need to do? )
What next? How to create a view that will force download of that image?
You can try this code, maybe need some caveats:
from django.core.servers.basehttp import FileWrapper
import mimetypes
def download_image(request, image_id):
img = ImageModel.objects.get(id=image_id)
wrapper = FileWrapper(open(img.file)) # img.file returns full path to the image
content_type = mimetypes.guess_type(filename)[0] # Use mimetypes to get file type
response = HttpResponse(wrapper,content_type=content_type)
response['Content-Length'] = os.path.getsize(img.file)
response['Content-Disposition'] = "attachment; filename=%s" % img.name
return response
I'm assuming there is a field .name in your ImageModel to get the name of the file in the second-to-last line ...filename=%s" % img.name You should edit the code to fit your project.
There is a field in an ImageField that is file, in the code here I use img.file to get the path to the file, you should change that for img.YOUR_IMAGE_FIELD.file or anything you need to get the path to the image
You need to use Content-Disposition header, take a look here:
Generating file to download with Django
Django Serving a Download File
A class based views-type exampe of this would be like this (i'm using python-magic to get the correct content-type for the file):
import os
import magic
from django.views.generic import View
from django.http import HttpResponse
from .models import ImageModel
class ImageDownloadView(View):
def get(self, request, *args, **kwargs):
image = ImageModel.objects.get(pk=self.kwargs['image_id'])
image_buffer = open(image.file.path, "rb").read()
content_type = magic.from_buffer(image_buffer, mime=True)
response = HttpResponse(image_buffer, content_type=content_type);
response['Content-Disposition'] = 'attachment; filename="%s"' % os.path.basename(image.file.path)
return response
This works for Django 1.10.7 but shouldn't be that different for Django 1.7
The other two answers are ok, but as advertised in many places using Django to serve an static file is not recommended for performance reasons. It is better to serve it using your web server (nginx/apache...).
You don't need an extra view to serve static files. Simply render a link to the file in your template:
Download this image!
Where object is an instance of ImageModel.
See django.db.models.fields.files.FieldFile.url
If you really want to have a view in an URL like www.example.com/image/download/1 you can simply write a view that redirect to the image URL obtained from the field.
Here is your cross browser safe download for files containing any character type
# Even better as it works in any browser (mobile and desktop)
def safe_name(file_name):
"""
Generates a safe file name, even those containing characters like ? and &
And your Kanji and Cyrillics are supported!
"""
u_file_name = file_name.encode('utf-8')
s_file_name = re.sub('[\x00-\xFF]', lambda c: '%%%02x' % ord(c.group(0)), u_file_name)
return s_file_name
# Handled by url(r'^/image/download/(\d+)/.+$
def safe_download_image(request, image_id):
"""
Safely downloads the file because the filename is part of the URL
"""
img = ImageModel.objects.get(id=image_id)
wrapper = FileWrapper(open(img.file)) # img.file returns full path to the image
content_type = mimetypes.guess_type(filename)[0] # Use mimetypes to get file type
response = HttpResponse(wrapper,content_type=content_type)
response['Content-Length'] = os.path.getsize(img.file)
# This works for most browsers, but IE will complain sometimes
response['Content-Disposition'] = "attachment;"
return response
def download_image(request, image_id):
img = ImageModel.objects.get(id=image_id)
redirect_do = safe_name(img.name)
return HttpResponseRedirect('/image/download/' + img_id + '/' + redirect_to)
It's doesn't work. I did something like this:
wrapper = FileWrapper(img.file) # img.file returns full path to the image
content_type = mimetypes.guess_type(str(img.file))[0] # Use mimetypes to get file type
response = HttpResponse(wrapper, content_type=content_type)
response['Content-Length'] = os.path.getsize(str(img.file))
response['Content-Disposition'] = "attachment; filename=%s" % img.name
where img points to my ImageField field. File is downloaded, but I can't open it. xUbuntu image viewer seys 'Not a JPEG file. starts with 0x89 0x50'

Django Serving a Download File

I'm trying to serve a txt file generated with some content and i am having some issues. I'vecreated the temp files and written the content using NamedTemporaryFile and just set delete to false to debug however the downloaded file does not contain anything.
My guess is the response values are not pointed to the correct file, hense nothing is being downloaded, heres my code:
f = NamedTemporaryFile()
f.write(p.body)
response = HttpResponse(FileWrapper(f), mimetype='application/force-download')
response['Content-Disposition'] = 'attachment; filename=test-%s.txt' % p.uuid
response['X-Sendfile'] = f.name
Have you considered just sending p.body through the response like this:
response = HttpResponse(mimetype='text/plain')
response['Content-Disposition'] = 'attachment; filename="%s.txt"' % p.uuid
response.write(p.body)
XSend requires the path to the file in
response['X-Sendfile']
So, you can do
response['X-Sendfile'] = smart_str(path_to_file)
Here, path_to_file is the full path to the file (not just the name of the file)
Checkout this django-snippet
There can be several problems with your approach:
file content does not have to be flushed, add f.flush() as mentioned in comment above
NamedTemporaryFile is deleted on closing, what might happen just as you exit your function, so the webserver has no chance to pick it up
temporary file name might be out of paths which web server is configured to send using X-Sendfile
Maybe it would be better to use StreamingHttpResponse instead of creating temporary files and X-Sendfile...
import urllib2;
url ="http://chart.apis.google.com/chart?cht=qr&chs=300x300&chl=s&chld=H|0";
opener = urllib2.urlopen(url);
mimetype = "application/octet-stream"
response = HttpResponse(opener.read(), mimetype=mimetype)
response["Content-Disposition"]= "attachment; filename=aktel.png"
return response

How to save file data from POST variable and load it back to response in Python Django?

I have a such problem - I am using Python 2.6 / Django 1.3 and I need to accept as POST variable with key 'f', which contains a binary data. After that, I need to save data in a file.
POST
T$topX$objectsX$versionY$archiverО©ҐR$0О©ҐО©ҐО©Ґull_=<---------------------- content of file -------------------->О©ҐО©Ґ_NSKeyedArchive(258:=CО©ҐО©Ґ
Code
from django.core.files.storage import default_storage
from django.core.files.base import ContentFile
def save(request):
upload_file = request.POST['f']
save_path = default_storage.save('%s%s' % (save_dir, filename),
ContentFile(upload_file))
When I am trying to do
nano /tmp/myfile.zip
It returns data like
T^#^#^#$^#^#^#t^#^#^#o^#^#^#p^#^#^#X^#^#^#$^#^#^#o^#^#^#b^#^#^#j^#^#^#e^#^#^#c^#^#^#t^#^#^#s^#^#^#X^#^#^#$^#^#^#v^#^#^#e^#^#^#r^#^#^#s^#^#^#i^#^#$
When its done, I am going to read saved file
def read(request):
user_file = default_storage.open(file_path).read()
file_name = get_filename(file_path)
response = HttpResponse(user_file, content_type = 'text/plain',
mimetype = 'application/force-download')
response['Content-Disposition'] = 'attachment; filename=%s' % file_name
response['Content-Length'] = default_storage.size(file_path)
return response
In case, when I am writing
print user_file
It returns a correct data, but when I am returning a HttpResponse it has a different data from a source
It would probably be easier, and more memory efficient if you just save the data into a file, and like #keckse said, let a browser stream it. Django is very inefficient in streaming data. It will all depend on the size of the data. If you want to stream it with django anyways, it can be done like this:
from django.http import HttpResponse
import os.path
import mimetypes
def stream(request, document, type=None):
doc = Document.objects.get(pk=document)
fsock = open(doc.file.path,"r")
file_name = os.path.basename(doc.file.path)
mime_type_guess = mimetypes.guess_type(file_name)
if mime_type_guess is not None:
response = HttpResponse(fsock, mimetype=mime_type_guess[0])
response['Content-Disposition'] = 'attachment; filename=' + file_name
return response
In your case you might want to set the mime type manually, you can try out application/octet-stream too. The mainpassing iterators difference is that you pass the "string" from file.read(), instead of the handle to the file directly. Please note: if you use read(), you will be loading the whole file into memory.
More on passing iterators to HttpResonse. And I might be wrong, but I think you can drop the content-type.

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