Downloading file in django

The default download backend transfers the file in chunks via Django, so it's definitely not the most efficient mechanism, but it uses only a small amount of memory important for large files and requires less resources than passing a file object directly to the response.

The default public downloads backend simply returns None. This default configuration should work with practically all servers, but it's not the most efficient solution.

Please take a look at the backends which are shipped with django-filetransfers to see if something fits your solution better. Many web servers at least Apache, Lighttpd, and nginx provide an "X-Sendfile" module which allows for handing off the actual file transfer to the web server. This is much more efficient than the default download backend, so you should install the required module for your web server and then configure the xsendfile download backend in your settings.

We also provide a backend which simply redirects to file. You have to make sure that file. This backend should work with the Amazon S3 and similar storage backends from the django-storages project. Just add the following to your settings. Alternatively, there's also a simple backend that merely points to a different URL.

You just need to specify a base URL and the backend appends file. This way you can, for instance, use the App Engine Blobstore for private files and Amazon S3 for public files:. Serves a file to the browser. This is used either for checking permissions before approving a downoad or as a fallback if the backend doesn't support publicly accessible URLs. We then make a GET request with requests in streaming mode, so it doesn't try to download the entire file in memory.

Instead it gives us chunks, which we save to a temporary file. This approach avoids causing problems if the files to download are big relative to available memory you never know when your user might attempt to set a two-hour full-HD movie as their avatar picture. The urlretrieve function also works in the same way. After we've downloaded the content, we seek to the beginning of opened file so we can read from the start , and tell the FileField to save it.

We use the same logic for naming the file as before. In this case, we haven't used any extra features the requests library gives us to avoid complicating the example. In the real world you can do anything the requests library supports here and if you don't need it, consider using the simpler urlretrieve approach.

I should have mentioned that I use Ajax to call this function but it never occurred to me that this could be an issue. Python Javascript Linux Cheat sheet Contact. Downloading a csv file in django If the file is static i.

If the file is dynamic , there are 2 options: Create it in memory and serve it from django. Update uploaded files Note that only the path to the file saved in that field in the database will be updated, but previously uploaded files will not be automatically deleted, requiring us to write our own logic to delete previously uploaded errors or files that need to be overwritten.

Also, if the uploaded file name is the same, then you will find that the file name behind the path of this field in the database has a random and messy string, because the uploaded file name conflicts.

To resolve this conflict, django changed your file name. View files that have been uploaded you will need to use our configuration above in the settings configuration file and url.

In practical projects, download functions are often needed, such as importing excel, pdf or file download.