setting “python_requires” with ">=3.7" is a better way to declare Python compatibility

[PyVCEchecker]

Hello!
I noticed such a declaration in setup.py

classes = """
    Programming Language :: Python :: 3
    Programming Language :: Python :: 3.7
    Programming Language :: Python :: 3.8
    Programming Language :: Python :: 3.9
    Programming Language :: Python :: 3.10
   ...
   """

And using the following code checking Python compatibility locally

PY37_OR_LESS = sys.version_info < (3, 7)
PYPY_VERSION = getattr(sys, 'pypy_version_info', None)
PYPY24_ATLEAST = PYPY_VERSION and PYPY_VERSION >= (2, 4)

if PY37_OR_LESS and not PYPY24_ATLEAST:
    raise Exception(E_UNSUPPORTED_PYTHON % (PYIMP, '3.7'))

I guess you want to set python>3.7. But I think it is a better way to declare Python compatibility by using the keyword argument python_requires than argument classifiers or checking compatibility locally for some reasons:

• Descriptions in python_requires will be reflected in the metadata
• “pip install” can check such metadata on the fly during distribution selection , and prevent from downloading and installing the incompatible package versions.
• If the user does not specify any version constraint, pip can automatically choose the latest compatible package version for users.

Way to improve:
modify setup() in setup.py, add python_requires keyword argument:

setup(…
     python_requires=">=3.7",
     …)

Thanks for your attention.
Best regrads,
PyVCEchecker