running this django project but its showing me this error in manage.py

Question

this is the error its showing me while running the django project of searchable dropdown list. I did exactly as mentioned in the youtube video but these are all the errors its showing me

File "manage.py", line 23, in <module>
    main()
  File "manage.py", line 19, in main
    execute_from_command_line(sys.argv)
  File "C:\ProgramData\Anaconda3\lib\site-packages\django\core\management\__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "C:\ProgramData\Anaconda3\lib\site-packages\django\core\management\__init__.py", line 345, in execute
    settings.INSTALLED_APPS
  File "C:\ProgramData\Anaconda3\lib\site-packages\django\conf\__init__.py", line 83, in __getattr__
    self._setup(name)
  File "C:\ProgramData\Anaconda3\lib\site-packages\django\conf\__init__.py", line 70, in _setup
    self._wrapped = Settings(settings_module)
  File "C:\ProgramData\Anaconda3\lib\site-packages\django\conf\__init__.py", line 177, in __init__
    mod = importlib.import_module(self.SETTINGS_MODULE)
  File "C:\ProgramData\Anaconda3\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "C:\Users\mahima\Downloads\dropdown\ddl\ddl\settings.py", line 58, in <module>
    'DIRS': [os.path.join(BASE_DIR,'templates')],
NameError: name 'os' is not defined

this is my manage.py file. I have mysql installed.Can anybody tell me how to fix all these errors? I'm a newcomer

#!/usr/bin/env python
"""Django's command-line utility for administrative tasks."""
import os
import sys


def main():
    """Run administrative tasks."""
    os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'ddl.settings')
    
    try:
        from django.core.management import execute_from_command_line
    except ImportError as exc:
        raise ImportError(
            "Couldn't import Django. Are you sure it's installed and "
            "available on your PYTHONPATH environment variable? Did you "
            "forget to activate a virtual environment?"
        ) from exc
    execute_from_command_line(sys.argv)


if __name__ == '__main__':
    main()

Answer 1

Try to add at top of file C:\Users\mahima\Downloads\dropdown\ddl\ddl\settings.py

import os

It is look like you missed import of module