Refactor /bnf/setup.py to use qualified imports

[Copilot]

Converts import style from from xxx import yyy to import xxx with qualified usage throughout the file.

Changes

• from pathlib import Path → import pathlib with pathlib.Path usage
• from setuptools import setup → import setuptools with setuptools.setup usage
• from setuptools.command.build_py import build_py → import setuptools.command.build_py with setuptools.command.build_py.build_py usage

No functional changes, imports now follow the preferred style convention.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>/bnf/setup.py 做一下变换</issue_title>
<issue_description>我不喜欢from xxx import yyy

我喜欢import xxx然后用的时候xxx.yyy</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes /bnf/setup.py 做一下变换 #142

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[Copilot]

Pull request overview

This PR refactors the import statements in bnf/setup.py to use qualified imports instead of the from xxx import yyy style, aligning with the author's preference for explicit module qualification at usage sites.

Key Changes:

• Converted three import statements from from style to module imports
• Updated all usages throughout the file to use fully qualified names

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

The class inheritance uses an unnecessarily verbose qualified path. While setuptools.command.build_py.build_py is technically correct, it impacts readability and goes against common Python conventions. Consider using a more concise approach like importing the module as an alias (e.g., from setuptools.command import build_py) or at minimum using the shorter setuptools.command.build_py module with an alias to access the class.