pip 与虚拟环境：Python 包管理完全指南

# 安装包
pip install requests
pip install requests==2.28.0  # 指定版本

# 升级包
pip install --upgrade requests

# 卸载包
pip uninstall requests

# 导出当前环境依赖
pip freeze > requirements.txt

# 安装依赖
pip install -r requirements.txt

# requirements.txt 示例
requests==2.28.0
numpy>=1.21.0
pandas
openai>=1.0.0
langchain>=0.1.0

# 使用国内镜像
pip install requests -i https://pypi.tuna.tsinghua.edu.cn/simple

# 持久化配置
pip config set global.index-url https://pypi.tuna.tsinghua.edu.cn/simple

# 创建虚拟环境
python -m venv venv

# 激活 (Linux/Mac)
source venv/bin/activate

# 激活 (Windows)
venv\Scripts\activate

# 退出
deactivate

my-project/
├── venv/              # 虚拟环境
├── src/               # 源代码
├── tests/             # 测试
├── requirements.txt   # 依赖
├── .gitignore
└── README.md

venv/
__pycache__/
*.py[cod]
.pytest_cache/
.env

[project]
name = "my-ai-app"
version = "0.1.0"
description = "AI Application"
requires-python = ">=3.10"
dependencies = [
    "openai>=1.0.0",
    "langchain>=0.1.0",
    "python-dotenv>=1.0.0",
]

[project.optional-dependencies]
dev = [
    "pytest>=7.0.0",
    "ruff>=0.1.0",
]

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

[tool.pytest.ini_options]
testpaths = ["tests"]

[tool.ruff]
line-length = 100

# 安装 uv
pip install uv

# 创建项目
uv init my-project
cd my-project

# 安装依赖
uv add requests
uv add langchain --group main
uv add pytest --group dev

# 创建虚拟环境
uv venv

# 运行脚本
uv run main.py