「動かして学ぶ！Pythonサーバレスアプリ開発入門」 サンプルコード

P150で SESSION_TYPE = dynamodb をコメントアウトしないとき

python manage.py init_db                                                     
Traceback (most recent call last):
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/pynamodb/connection/base.py", line 548, in get_meta_table
    data = self.dispatch(DESCRIBE_TABLE, operation_kwargs)
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/pynamodb/connection/base.py", line 329, in dispatch
    data = self._make_api_call(operation_name, operation_kwargs, settings)
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/pynamodb/connection/base.py", line 378, in _make_api_call
    prepared_request = self._create_prepared_request(request_dict, settings)
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/pynamodb/connection/base.py", line 306, in _create_prepared_request
    self._sign_request(request)
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/pynamodb/connection/base.py", line 298, in _sign_request
    auth.add_auth(request)
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/botocore/auth.py", line 373, in add_auth
    raise NoCredentialsError()
botocore.exceptions.NoCredentialsError: Unable to locate credentials

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "manage.py", line 9, in <module>
    manager.run()
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/flask_script/__init__.py", line 417, in run
    result = self.handle(argv[0], argv[1:])
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/flask_script/__init__.py", line 386, in handle
    res = handle(*args, **config)
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/flask_script/commands.py", line 216, in __call__
    return self.run(*args, **kwargs)
  File "/Users/shinriyo/development/python_apps/application/flask_blog/scripts/db.py", line 9, in run
    if not Entry.exists():
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/pynamodb/models.py", line 753, in exists
    cls._get_connection().describe_table()
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/pynamodb/connection/table.py", line 290, in describe_table
    return self.connection.describe_table(self.table_name)
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/pynamodb/connection/base.py", line 748, in describe_table
    tbl = self.get_meta_table(table_name, refresh=True)
  File "/Users/shinriyo/.local/share/virtualenvs/application-jAa1F8aU/lib/python3.8/site-packages/pynamodb/connection/base.py", line 551, in get_meta_table
    raise TableError("Unable to describe table: {}".format(e), e)
pynamodb.exceptions.TableError: Unable to describe table: Unable to locate credentials