Read file in Django Management Command

Question

I'm trying to read credentials for the Google Sheets API using gspread. I wrote the following code:

class Command(BaseCommand):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

    def handle(self, *args, **kwargs):
        scope = ['https://spreadsheets.google.com/feeds',
         'https://www.googleapis.com/auth/drive']

        credentials = ServiceAccountCredentials.from_json_keyfile_name('/static/json/spreadsheets.json', scope)

        gc = gspread.authorize(credentials)

        wks = gc.open("Where is the money Lebowski?").sheet1

        self.stdout.write(self.style.SUCCESS('Succesfully ran "sheets" command'))

Reading the file returns the following error:

FileNotFoundError: [Errno 2] No such file or directory: 'static/json/spreadsheets.json'

I tried multiple paths like:

• '~/static/json/spreadsheets.json'
• '/json/spreadsheets.json'
• 'spreadsheets.json'

But none seem to work. Could anybody help me out here?

Answer 1

When you use an absolute path, it is taken literally i.e. from starting from the root of the filesystem i.e. /.

When you use a relative path i.e. without / at start, it is resolved from the directory where script is invoked from, not where the script actually lies in the filesystem.

So when you invoke the Django management command via e.g. ./manage.py <command>, it looks for a path starting from the current directory of manage.py i.e. os.path.dirname('manage.py'). If you give the path as static/json/spreadsheets.json, the full path it looks for is:

os.path.join(
    os.path.abspath(os.path.dirname('manage.py')),
    '/static/json/spreadsheets.json'
)

So you need to make sure you have the spreadsheets.json file in the right directory. A better approach would be to use an absolute path for these kind of scenarios. If you're on GNU/Linux, you can use:

readlink -f static/json/spreadsheets.json

to get the absolute path.

---

Also, rather than hardcoding the file, you should take the file as an argument to the management command. Django management command uses argparse for argument parsing, so you can take a peek at the doc.