Hi 大家好，

今天要介紹的內容是如何安裝Poetry管理工具，並且使用Poetry的功能來建立虛擬環境和相關套件。

Q: 為什麼要建立虛擬環境？
A: 在使用Python程式語言開發相關項目時候，虛擬環境可以說是非常重要的一環。
　原因是：
　　* 虛擬環境就是一種完全獨立的開發環境
　　* 依賴隔離：隔離了不同專案開發時候套件的相互依賴性和影響的關係
　　* 簡化部屬：確保在開發環境中安裝和測試的所有依賴都能被正確記錄，在部屬時可以精準重現
　　* 提高安全性：使用虛擬環境可以避免意外修改系統的全局 Python 環境

接下來我們就來實作如何安裝的步驟：
※ 我所示範的步驟，是自己嘗試安裝過的過程，但也只是其中一種方法提供參考，請斟酌服用

1. 安裝Poetry

   • 安裝 scoop 工具

   > Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
   > Invoke-RestMethod -Uri https://get.scoop.sh | Invoke-Expression
   

   

   • 安裝 pipx 工具

   scoop install pipx
   

   

   • 安裝 poetry
     以系統管理員身分執行PowerShell 7

   pipx install poetry
   

   PS D:\Project\5xcampus\Python\20240725_python_demo> pipx install poetry
    ⚠️  File exists at C:\Users\Eric\.local\bin\poetry.exe and points to 
    C:\Users\Eric\.local\bin\poetry.exe, not
    C:\Users\Eric\pipx\venvs\poetry\Scripts\poetry.exe. Not modifying.
      installed package poetry 1.8.3, installed using Python 3.12.4
      These apps are now globally available
        - poetry.exe (symlink missing or pointing to unexpected location)
    done! ✨ 🌟 ✨
    PS D:\Project\5xcampus\Python\20240725_python_demo>
   

   查看目前安裝版本

   PS D:\Project\5xcampus\Python\20240725_python_demo> poetry --version
   Poetry (version 1.8.3)
   PS D:\Project\5xcampus\Python\20240725_python_demo>
   

2. 使用Poetry confing 查看設定檔案

   PS D:\Project\5xcampus\Python\practice> poetry config --list
   cache-dir = "C:\\Users\\Eric\\AppData\\Local\\pypoetry\\Cache"
   experimental.system-git-client = false
   installer.max-workers = null
   installer.modern-installation = true
   installer.no-binary = null
   installer.parallel = true
   keyring.enabled = true
   solver.lazy-wheel = true
   virtualenvs.create = true
   virtualenvs.in-project = false
   virtualenvs.options.always-copy = false
   virtualenvs.options.no-pip = false
   virtualenvs.options.no-setuptools = false
   virtualenvs.options.system-site-packages = false
   virtualenvs.path = "{cache-dir}\\virtualenvs"  #  C:\Users\Eric\AppData\Local\pypoetry\Cache\virtualenvs
   virtualenvs.prefer-active-python = false
   virtualenvs.prompt = "{project_name}-py{python_version}"
   warnings.export = true
   PS D:\Project\5xcampus\Python\practice>
   

   其中的環境設定檔案中的 virtualenvs.in-project 預設會是 null 或是 false
   這行配置選項表示: 要不要在Poetry啟動一個新的shell的時候自動建立虛擬環境

   flase: 之後可以自己手動建立 poetry new .venv
true: 啟動shell時候自動建立
   這裡我們先把配置改為true

   PS D:\Project\5xcampus\Python\practice> poetry config virtualenvs.in-project true
   PS D:\Project\5xcampus\Python\practice> poetry config --list
   cache-dir = "C:\\Users\\Eric\\AppData\\Local\\pypoetry\\Cache"
   experimental.system-git-client = false
   installer.max-workers = null
   installer.modern-installation = true
   installer.no-binary = null
   installer.parallel = true
   keyring.enabled = true
   solver.lazy-wheel = true
   virtualenvs.create = true
   virtualenvs.in-project = true
   virtualenvs.options.always-copy = false
   virtualenvs.options.no-pip = false
   virtualenvs.options.no-setuptools = false
   virtualenvs.options.system-site-packages = false
   virtualenvs.path = "{cache-dir}\\virtualenvs"  # C:\Users\Eric\AppData\Local\pypoetry\Cache\virtualenvs
   virtualenvs.prefer-active-python = false
   virtualenvs.prompt = "{project_name}-py{python_version}"
   warnings.export = true
   PS D:\Project\5xcampus\Python\practice>
   

3. 建立一新資料夾practice，並且進入資料夾

4. 在當前目錄下建立一個 pyproject.toml 文件來管理項目的依賴和配置

   poetry init => 會有互動式問答，詢問一些關於項目的基本信息，可自行定義
   

   PS D:\Project\5xcampus\Python\practice> poetry init
   A pyproject.toml file with a poetry section already exists.
   PS D:\Project\5xcampus\Python\practice> poetry init
   
   This command will guide you through creating your pyproject.toml config.
   
   Package name [practice]:
   Version [0.1.0]:
   Description []:
   Author [erichsu <filafila0521@gmail.com>, n to skip]:
   License []:
   Compatible Python versions [^3.12]:
   
   Would you like to define your main dependencies interactively? (yes/no) [yes]
   You can specify a package in the following forms:
     - A single name (requests): this will search for matches on PyPI
     - A name and a constraint (requests@^2.23.0)
     - A git url (git+https://github.com/python-poetry/poetry.git)
     - A git url with a revision (git+https://github.com/python-poetry/poetry.git#develop)
     - A file path (../my-package/my-package.whl)
     - A directory (../my-package/)
     - A url (https://example.com/packages/my-package-0.1.0.tar.gz)
   
   Package to add or search for (leave blank to skip):
   
   Would you like to define your development dependencies interactively? (yes/no) [yes]
   Package to add or search for (leave blank to skip):
   
   Generated file
   
   [tool.poetry]
   name = "practice"
   version = "0.1.0"
   description = ""
   authors = ["erichsu <filafila0521@gmail.com>"]
   readme = "README.md"
   
   [tool.poetry.dependencies]
   python = "^3.12"
   
   
   [build-system]
   requires = ["poetry-core"]
   build-backend = "poetry.core.masonry.api"
   
   
   Do you confirm generation? (yes/no) [yes]
   PS D:\Project\5xcampus\Python\practice>
   

   poetry init -n => 會省略互動式問答，基本訊息都採用預設方式 
   

   PS D:\Project\5xcampus\Python\practice> poetry init -n
   PS D:\Project\5xcampus\Python\practice>
   

   查看pyproject.toml內容

   PS D:\Project\5xcampus\Python\practice> cat .\pyproject.toml
   [tool.poetry]
   name = "practice"
   version = "0.1.0"
   description = ""
   authors = ["xxx <xxx@gmail.com>"]
   readme = "README.md"
   
   [tool.poetry.dependencies]
   python = "^3.12"
   
   
   [build-system]
   requires = ["poetry-core"]
   build-backend = "poetry.core.masonry.api"
   PS D:\Project\5xcampus\Python\practice>
   

5. 使用Poetry shell啟動一新的虛擬環境

   PS D:\Project\5xcampus\Python\practice> poetry shell
   Creating virtualenv practice in D:\Project\5xcampus\Python\practice\.venv
   Spawning shell within D:\Project\5xcampus\Python\practice\.venv
   PowerShell 7.4.3
   
      A new PowerShell stable release is available: v7.4.4
      Upgrade now, or check out the release page at:
        https://aka.ms/PowerShell-Release?tag=v7.4.4
   
   (practice-py3.12) PS D:\Project\5xcampus\Python\practice> ls
   
       Directory: D:\Project\5xcampus\Python\practice
   
   Mode                 LastWriteTime         Length Name
   ----                 -------------         ------ ----
   d----          2024/8/3 下午 02:55                .venv
   -a---          2024/8/3 下午 02:52            280 pyproject.toml
   
   (practice-py3.12) PS D:\Project\5xcampus\Python\practice>
   

   其中(practice-py3.12)字樣表示已經進入到虛擬環境中

6. 使用poetry add <套件名稱>，來安裝相關套件

   (practice-py3.12) PS D:\Project\5xcampus\Python\practice> poetry add django
   Using version ^5.0.7 for django
   
   Updating dependencies
   Resolving dependencies... (0.2s)
   
   Package operations: 4 installs, 0 updates, 0 removals
   
     - Installing asgiref (3.8.1)
     - Installing sqlparse (0.5.1)
     - Installing tzdata (2024.1)
     - Installing django (5.0.7)
   
   Writing lock file
   (practice-py3.12) PS D:\Project\5xcampus\Python\practice>
   

7. 使用poetry show查看是否安裝成功

   (practice-py3.12) PS D:\Project\5xcampus\Python\practice> poetry show
   Error: poetry.lock not found. Run `poetry lock` to create it.
   (practice-py3.12) PS D:\Project\5xcampus\Python\practice> poetry lock
   Updating dependencies
   Resolving dependencies... (0.1s)
   
   Writing lock file
   (practice-py3.12) PS D:\Project\5xcampus\Python\practice> poetry show
   asgiref  3.8.1  ASGI specs, helper code, and adapters
   django   5.0.7  A high-level Python web framework that encourages rapid development and clean, pragmatic design.
   sqlparse 0.5.1  A non-validating SQL parser.
   tzdata   2024.1 Provider of IANA time zone data
   (practice-py3.12) PS D:\Project\5xcampus\Python\practice>
   

8. 如何退出虛擬環境 ( exit、Ctrl+D )

   (practice-py3.12) PS D:\Project\5xcampus\Python\practice> exit
   PS D:\Project\5xcampus\Python\practice>
   

以上就是今天要介紹的內容，我們明天見～