attempted relative import with no known parent package

This error message is raised when attempting to use a relative import in Python, but the parent package or module is not known or cannot be found.

A relative import is a way to import a module or package relative to the current module, rather than using an absolute import that specifies the full path to the module. For example, if you have a package structure like this:

mypackage/
    __init__.py
    module1.py
    subpackage/
        __init__.py
        module2.py

You could use a relative import in `module2.py` to import `module1.py` like this:

from ..module1 import some_function

The `..` means to go up one level in the package hierarchy to find the parent package, which in this case is `mypackage`.

If you get the error message "attempted relative import with no known parent package", it means that Python cannot find the parent package or module. This can happen if:

- The module or package you're trying to import from does not have a parent package, or it is not structured correctly.
- You are trying to run the module directly as the main script, rather than importing it as a module. Relative imports only work when the module is imported as part of a package.
- You are using an older version of Python that does not support relative imports (they were introduced in Python 2.5).

To fix this error, make sure that your package structure is correct and that you are importing modules correctly. If you are using an older version of Python, you may need to switch to using absolute imports instead.