Python 3.8：如何移除__init__.py实现无侵入式专业版功能扩展

Great question! Let's work through a clean solution that meets all your requirements: sharing a single codebase, enabling pro features just by adding files, no overwrites/deletions, and zero pro-specific code in the standard edition.

Core Idea #

We'll use Python's auto-import mechanism (via .pth files) and dynamic function wrapping to inject pro features without touching standard edition code. Here's how to implement it step by step:

1. Standard Edition Setup (No Pro Code Anywhere)

First, adjust your standard edition to have clean, pro-free code:

Directory Structure:

fooble.py
foo/
    __init__.py       # Standard-only, no pro references
    test_decorate.py

foo/__init__.py (Standard Edition):
This file only imports the standard function—no pro logic at all:

# Pure standard edition code: import core function
from .test_decorate import do_something

foo/test_decorate.py (Unchanged):

def do_something(name):
    print(f"STANDARD do something {name}")

fooble.py (Unchanged):

from foo import do_something
do_something('xxx')

2. Pro Edition: Only Add These Files

You won't modify any standard edition files. Just add two new files for the pro version:

File 1: foo/test_decorate_pro.py

This module wraps the standard function dynamically:

import wrapt
import foo

@wrapt.decorator
def pro_do_something(wrapped, instance, args, kwargs):
    print(f"PRO do something args[0]", args, kwargs)
    return wrapped(*args, **kwargs)

# Replace the standard function with the wrapped pro version
foo.do_something = pro_do_something(foo.do_something)

File 2: foo-pro-autoimport.pth

This tells Python to automatically load the pro module on startup. Place this file in your Python site-packages directory (or use your packaging tool like setuptools to install it automatically):

import foo.test_decorate_pro

3. How It Works

• Standard Only: When only the standard edition is installed, foo.do_something is the original standard function—no pro code runs, no extra files needed.
• Pro Enabled: When you add the pro files, Python reads the .pth file on startup and auto-imports foo.test_decorate_pro. This module dynamically replaces foo.do_something with the wrapped pro version. Any code that imports do_something (like fooble.py) will automatically use the pro feature without changes.

Alternative: No Standard __init__.py

If you really want to remove the standard edition's foo/__init__.py, adjust things to use a namespace package:

Standard Edition Structure:

fooble.py
foo/
    test_decorate.py  # No __init__.py here

Update fooble.py:

from foo.test_decorate import do_something
do_something('xxx')

Pro Files:
Keep the same foo/test_decorate_pro.py (modified slightly to target the module directly):

import wrapt
import sys
from foo.test_decorate import do_something as original_do_something

@wrapt.decorator
def pro_do_something(wrapped, instance, args, kwargs):
    print(f"PRO do something args[0]", args, kwargs)
    return wrapped(*args, **kwargs)

# Replace the function in the standard module
sys.modules['foo.test_decorate'].do_something = pro_do_something(original_do_something)

Add the same .pth file to auto-import this module.

This setup still keeps pro code completely separate, requires only adding files, and avoids any overwrites.

内容的提问来源于stack exchange，提问作者Duke Dougal