pip、虚拟环境与项目结构

# 安装包
pip install requests
pip install requests==2.31.0          # 指定版本
pip install requests>=2.28             # 最低版本要求

# 升级
pip install --upgrade requests

# 卸载
pip uninstall requests

# 查看已安装的包
pip list
pip list --outdated                    # 查看可升级的包

# 查看包信息
pip show requests

# 导出 / 导入依赖
pip freeze > requirements.txt         # 导出当前环境所有依赖
pip install -r requirements.txt        # 根据 requirements.txt 安装

# 创建虚拟环境
python3 -m venv .venv

# 激活虚拟环境
# macOS / Linux:
source .venv/bin/activate

# Windows:
.venv\Scripts\activate

# 激活后，pip 指向虚拟环境内的版本
(.venv) $ pip install requests
(.venv) $ pip list
# Package    Version
# pip        24.0
# setuptools 75.8.0
# requests   2.31.0

# 退出虚拟环境
deactivate

.venv/
├── bin/                  # Linux/macOS 可执行文件
│   ├── python            # 虚拟环境专属的 Python
│   ├── pip
│   └── activate
├── lib/                  # 库文件（隔离的 site-packages）
│   └── python3.x/site-packages/
└── pyvenv.cfg           # 配置文件

# requirements.txt
requests==2.31.0
flask==3.0.0

# requirements.txt（基础依赖）
flask==3.0.0

# requirements-dev.txt（开发依赖）
-r requirements.txt    # 包含基础依赖
pytest==8.0.0
black==24.0.0
mypy==1.8.0

pip install -r requirements.txt
pip install -r requirements-dev.txt

# pyproject.toml
[project]
name = "myproject"
version = "0.1.0"
description = "我的 Python 项目"
requires-python = ">=3.10"
dependencies = [
    "requests>=2.31.0",
    "flask>=3.0.0",
]

[project.optional-dependencies]
dev = [
    "pytest>=8.0.0",
    "black>=24.0.0",
    "mypy>=1.8.0",
]

[project.scripts]
myproject = "myproject.cli:main"

[build-system]
requires = ["setuptools>=61.0"]
build-backend = "setuptools.build_meta"

pip install -e ".[dev]"   # 可编辑模式安装 + dev 依赖

myproject/
├── .venv/                    # 虚拟环境（通常加入 .gitignore）
├── src/                      # 源代码目录
│   └── myproject/
│       ├── __init__.py
│       ├── main.py
│       ├── config.py
│       └── utils.py
├── tests/                    # 测试目录
│   ├── __init__.py
│   ├── test_main.py
│   └── test_utils.py
├── docs/                     # 文档
├── pyproject.toml            # 项目配置
├── requirements.txt          # 依赖清单（可选）
├── README.md
├── .gitignore
└── LICENSE

# src/myproject/__init__.py
"""myproject: 一个示例包"""

__version__ = "0.1.0"

from .main import main
from .utils import helper

__all__ = ["main", "helper", "__version__"]

# Python
__pycache__/
*.py[cod]
*$py.class
*.so
.Python
build/
dist/
*.egg-info/
.eggs/

# 虚拟环境
.venv/
venv/
ENV/

# IDE
.vscode/
.idea/
*.swp
*.swo

# 测试
.pytest_cache/
.coverage
htmlcov/

# 环境变量
.env

# 安装 Poetry
curl -sSL https://install.python-poetry.org | python3 -

# 初始化项目
poetry new myproject

# 添加依赖
poetry add requests
poetry add --group dev pytest

# 安装依赖
poetry install

# 锁定并更新
poetry lock
poetry update

# 运行脚本
poetry run python main.py

# 构建发布包
poetry build