Why can’t find_packages() find one of my code packages?

Question

I’m trying to generate a distribution package for Pypi by setuptools. The problem is that the function find_packages cannot find one of my packet folders, called win32.

The directory tree is as follows:

PyMemoryEditor/
    process/
    win32/ 
    __init__.py
setup.py

The return of the function is always this:

['PyMemoryEditor', 'PyMemoryEditor.process']

I have already tried renaming the folder to several names (win32tools, test, my guess, etc), but still no success. What’s going on? I’m doing something wrong?

Below is the complete code of setup.py:

from PyMemoryEditor import __version__
from setuptools import setup, find_packages

with open("README.md") as file:
    README = file.read()

setup(
    name = "PyMemoryEditor",
    version = __version__,
    description = "Process memory reader and writer.",
    long_description = README,
    long_description_content_type = "text/markdown",
    author = "My Name",
    url = "https://github.com/JeanExtreme002/PyMemoryEditor",
    license = "MIT",
    keywords = "memory writer reader",
    packages = find_packages(exclude = ("tests", "docs")),
    install_requires = ["pywin32", "psutil"]
)