django test app error - Got an error creating the test database: permission denied to create database

When Django runs the test suite, it creates a new database, in your case test_finance. The postgres user with username django does not have permission to create a database, hence the error message.

When you run migrate or syncdb, Django does not try to create the finance database, so you don't get any errors.

You can add the createdb permission to the django user by running the following command in the postgres shell as a superuser (hat tip to this stack overflow answer).

=> ALTER USER django CREATEDB;

Note: The username used in the ALTER USER <username> CREATEDB; command needs to match the database user in your Django settings files. In this case, the original poster, had the user as django the above answer.

I have found interesting solution to your problem.
In fact for MySQL you can grant privileges for non-existing database.
So you can add name 'test_finance' for your test database in your settings:

    DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2', # Add 'postgresql_psycopg2', 'mysql', 'sqlite3' or 'oracle'.
        'NAME': 'finance',                      # Or path to database file if using sqlite3.
        'USER': 'django',                      # Not used with sqlite3.
        'PASSWORD': 'mydb123',                  # Not used with sqlite3.
        'HOST': '127.0.0.1',                      # Set to empty string for localhost. Not used with sqlite3.
        'PORT': '',                      # Set to empty string for default. Not used with sqlite3.
        'TEST': {
            'NAME': 'test_finance',
        },
    }
}

start MySQL shell as the root user:

mysql -u root -p

and now grant all privileges to this non-existing database in MySQL:

GRANT ALL PRIVILEGES ON test_finance.* TO 'django'@'localhost';

Now Django will start tests without any problems.

In the case of Postgres, the user must have createdb permission.

ALTER ROLE miriam CREATEDB;

See this documentation: https://docs.djangoproject.com/en/2.0/topics/testing/overview/#the-test-database