How to use call_command with dumpdata command to save json to file

I am trying to use the call_command method to call the dumpdata command. Manually, I use it as follows to save the data to a file.

python manage.py dumpdata appname_one appname_two > /path/to/save/file.json

and it saves the json file. Now, I am in a situation where I need to call this command using the call_command method.

I am able to print out the json from the command using the following:

from django.core.management import call_command

call_command('dumpdata', 'appname_one', 'appname_two')

Is there a way I can save the given data to a file like we do it from the command line?

had to redirect sys.stdout to the file in order to achieve the above. Something like.

import sys

from django.core.management import call_command


sysout = sys.stdout
sys.stdout = open('filename.json', 'w')
call_command('dumpdata', 'appname_one', 'appname_two')
sys.stdout = sysout

An even better way is to use Django's built-in stdout redirection for their command modules. See docs here.

If you want to manipulate the stream before sending it to a file, you can also pass it a StringIO buffer:

import os
from cStringIO import StringIO

from django.core import management

def create_fixture(app_name, filename):
    buf = StringIO()
    management.call_command('dumpdata', app_name, stdout=buf)
    buf.seek(0)
    with open(filename, 'w') as f:
        f.write(buf.read())