如何在矩池云使用 Poetry 管理项目环境

官网介绍：Poetry is a tool for dependency management and packaging in Python. It allows you to declare the libraries your project depends on and it will manage (install/update) them for you.

https://python-poetry.org/docs/

Poetry 是 Python 中用于依赖管理和打包的工具。它允许您声明项目所依赖的库，并且它将为您管理(安装/更新)它们。

本文将带大家在矩池云上安装并使用 Poetry 管理项目环境，默认你已经在矩池云上租用了一台机器，如果不知道如何在矩池云租用服务器，可以查看矩池云新手入门教程。

安装 Poetry

pip install poetry

创建一个 poetry 项目目录

首先我们进入 /home 目录中，然后执行 poetry new 指令，即可新建一个 poetry 项目，默认包含下面几部分。

cd /home
poetry new my-project
cd my-project
tree

my-project
├── README.rst   # 项目说明
├── my_project   # 项目文件目录
│   └── __init__.py
├── pyproject.toml  # poetry配置文件 重要
└── tests   # 测试文件
    ├── __init__.py
    └── test_my_project.py

上面目录结构中，最重要的是 pyproject.toml，里面默认包含了下面内容：

[tool.poetry]
name = "my-project"
version = "0.1.0"
description = ""
authors = ["Your Name <you@example.com>"]

[tool.poetry.dependencies]
python = "^3.8"

[tool.poetry.dev-dependencies]
pytest = "^5.2"

[build-system]
requires = ["poetry-core>=1.0.0"]
build-backend = "poetry.core.masonry.api"

• tool.poetry 记录项目名称、版本、基本描述和作者
• tool.poetry.dependencies 记录项目依赖工具和版本，比如 python
• tool.poetry.dev-dependencies 记录项目依赖的 python 包
• build-system 记录 Poetry 环境构建工具

poetry 创建、进入虚拟环境

• 创建虚拟环境 poetry env use 本地 python 解释器路径

(myconda) root@c6854bdc088b:/home/my-project# poetry env use /root/miniconda3/envs/myconda/bin/python
Creating virtualenv my-project-zjY4rh4o-py3.8 in /root/.cache/pypoetry/virtualenvs
Using virtualenv: /root/.cache/pypoetry/virtualenvs/my-project-zjY4rh4o-py3.8

• 查看虚拟环境基本信息

(myconda) root@c6854bdc088b:/home/my-project# poetry env info

Virtualenv
Python:         3.8.2
Implementation: CPython
Path:           /root/.cache/pypoetry/virtualenvs/my-project-zjY4rh4o-py3.8
Valid:          True

System
Platform: linux
OS:       posix
Python:   /root/miniconda3/envs/myconda

• 进入虚拟环境

(myconda) root@c6854bdc088b:/home/my-project# poetry shell
Spawning shell within /root/.cache/pypoetry/virtualenvs/my-project-zjY4rh4o-py3.8
sh-4.4# . /root/.cache/pypoetry/virtualenvs/my-project-zjY4rh4o-py3.8/bin/activate
(my-project-zjY4rh4o-py3.8) sh-4.4# pip list
Package    Version
---------- -------
pip        22.0.4
setuptools 62.1.0
wheel      0.37.1
(my-project-zjY4rh4o-py3.8) sh-4.4# 

poetry 常用指令

• 安装第三方包

进入虚拟环境后，我们可以直接 pip innstall 包名 安装自己需要的第三方包，不过这样安装包不会记录到 pyproject.toml 中。

# poetry shell 进入虚拟环境后，可以直接pip install 包名安装
(my-project-zjY4rh4o-py3.8) sh-4.4# pip install pandas
Looking in indexes: https://mirrors.aliyun.com/pypi/simple/
Collecting pandas
  Downloading https://mirrors.aliyun.com/pypi/packages/12/07/e82b5de
...
Successfully installed numpy-1.22.3 pandas-1.4.2 python-dateutil-2.8.2 pytz-2022.1 six-1.16.0
(my-project-zjY4rh4o-py3.8) sh-4.4# pip list
Package         Version
--------------- -------
numpy           1.22.3
pandas          1.4.2
pip             22.0.4
python-dateutil 2.8.2
pytz            2022.1
setuptools      62.1.0
six             1.16.0
wheel           0.37.1

不进入虚拟环境，我们可以通过 poetry add 包名来安装，同时会生成一个 poetry.lock 文件，记录安装包相关依赖。

# 不进入虚拟环境
(myconda) root@cd90f1a3f442:/home/my-project# poetry add pendulum@latest
Using version ^2.1.2 for pendulum

Updating dependencies
Resolving dependencies... (59.4s)

Writing lock file

Package operations: 10 installs, 0 updates, 0 removals

  • Installing pyparsing (3.0.8)
  • Installing attrs (21.4.0)
  • Installing more-itertools (8.12.0)
  • Installing packaging (21.3)
  • Installing pluggy (0.13.1)
  • Installing py (1.11.0)
  • Installing pytzdata (2020.1)
  • Installing wcwidth (0.2.5)
  • Installing pendulum (2.1.2)
  • Installing pytest (5.4.3)

• 查看安装的包依赖关系 poetry show -t

(myconda) root@cd90f1a3f442:/home/my-project# poetry show -t
pendulum 2.1.2 Python datetimes made easy
├── python-dateutil >=2.6,<3.0
│   └── six >=1.5 
└── pytzdata >=2020.1
pytest 5.4.3 pytest: simple powerful testing with Python
├── atomicwrites >=1.0
├── attrs >=17.4.0
├── colorama *
├── more-itertools >=4.0.0
├── packaging *
│   └── pyparsing >=2.0.2,<3.0.5 || >3.0.5 
├── pluggy >=0.12,<1.0
├── py >=1.5.0
└── wcwidth *

• 移除安装的第三方包 poetry remove 包名，移除指定第三方包的同时会卸载相关依赖包。

(myconda) root@cd90f1a3f442:/home/my-project# poetry remove pendulum
Updating dependencies
Resolving dependencies... (0.1s)

Writing lock file

Package operations: 0 installs, 0 updates, 4 removals

  • Removing pendulum (2.1.2)
  • Removing python-dateutil (2.8.2)
  • Removing pytzdata (2020.1)
  • Removing six (1.16.0)

• 导出项目依赖

poetry export -f requirements.txt --output requirements.txt

常用参数：

--format (-f): 导出文件格式，目前仅支持requirements.txt
--output (-o): 导出文件名称

• 查看 poetry 全局配置 poetry config --list

(myconda) root@cd90f1a3f442:/home/my-project# poetry config --list
# poetry缓存目录
cache-dir = "/root/.cache/pypoetry"
experimental.new-installer = true
installer.parallel = true
# 默认 true，进行poetry add/install 时如果没有虚拟环境，就创建一个，如果为 false，没有虚拟环境就安装到系统环境中
virtualenvs.create = true
# 在项目根目录创建虚拟环境
virtualenvs.in-project = null
# 虚拟环境目录
virtualenvs.path = "{cache-dir}/virtualenvs"  # /root/.cache/pypoetry/virtualenvs

• 设置 poetry 全局配置值 poetry config virtualenvs.create false --local

(myconda) root@cd90f1a3f442:/home/my-project# poetry config virtualenvs.create false --local
(myconda) root@cd90f1a3f442:/home/my-project# poetry config --list
cache-dir = "/root/.cache/pypoetry"
experimental.new-installer = true
installer.parallel = true
virtualenvs.create = false
virtualenvs.in-project = null
virtualenvs.path = "{cache-dir}/virtualenvs"  # /root/.cache/pypoetry/virtualenvs

执行后，会在项目目录下生成一个 poetry.toml 文件，记录了修改的配置名和对应的值，--local 表示这是修改本项目的配置。

更多相关指令

poetry install  # 通过项目目录中的pyproject.toml安装相关依赖
poetry check  # 检查依赖关系
poetry search requests  # 查找可用的相关包信息
poetry lock # 更新 pyproject.toml 中依赖版本，加--no-update只更lock新文件，不更新包版本
poetry version  # 查看poetry版本
...

更多使用方法，可以阅读学习官方文档：https://python-poetry.org/docs/cli