class Test:
    name = 'tom'
    age = 0
    __weight = 0
    def __init__(self,n,a,w):
        self.name = n
        self.age = a
        self.__weight = w
    def speak(self):
        print("Test model: ",self.name,self.age, self.__weight)

import testModel
testModel.Test("tom", 0, 1).speak()
# Test model:  tom 0 1

testPackages/
        ├── __init__.py
        └── testModel.py

from testPackages import testModel
testModel.Test("tom", 0, 1).speak()
# Test model:  tom 0 1

testPackages/
        ├── __init__.py
        ├── add.py
        └── testModel.py

def add(a, b):
    return a + b

import testPackages.add
add = testPackages.add.add

import testPackages
testPackages.add(1,2)
# 3

packaging_tutorial/
├── LICENSE
├── pyproject.toml  #使用什么工具（pip或build）構建項目
├── README.md
├── src/
│   └── example_package/
│       ├── __init__.py
│       └── example.py
└── tests/  #例子數(shù)據(jù)

[build-system]
requires = ["setuptools>=42"]
build-backend = "setuptools.build_meta"

import setuptools
with open("README.md", "r", encoding="utf-8") as fh:
    long_description = fh.read()
setuptools.setup(
    name="testPackages",
    version="2.2.1",
    author="Author",
    author_email="author@example.com",
    description="A small example package",
    long_description=long_description,
    long_description_content_type="text/markdown",
    url="http://baidu.com/",
    classifiers=[
        "Programming Language :: Python :: 3",
        "License :: OSI Approved :: MIT License",
        "Operating System :: OS Independent",
    ],
    package_dir={"": "src"},
    packages=setuptools.find_packages(where="src"),
    python_requires=">=3.6",
)

python3 setup.py sdist

python3 -m pip install ./dist/testPackages-2.2.1.tar.gz

from testPackages import add
add.add(1,2)
# 3
#在__init__.py構建了add = testPackages.add.add，所以可以直接使用
add(1,2)
# 3