[Python] beyond top level package error in relative import

It seems there are already quite some questions here about relative import in python 3, but after going through many of them I still didn't find the answer for my issue. so here is the question.

I have a package shown below

package/
__init__.py
A/
__init__.py
foo.py
test_A/
__init__.py
test.py


and I have a single line in test.py:

from ..A import foo


now, I am in the folder of package, and I run

python -m test_A.test


I got message

"ValueError: attempted relative import beyond top-level package"


but if I am in the parent folder of package, e.g., I run:

cd ..
python -m package.test_A.test


everything is fine.

Now my question is: when I am in the folder of package, and I run the module inside the test_A sub-package as test_A.test, based on my understanding, ..A goes up only one level, which is still within the package folder, why it gives message saying beyond top-level package. What is exactly the reason that causes this error message?

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