Hi 大家好，

今天要開始介紹基礎語法中的函數進階篇之續集，那我們開始吧!

模組(Module)

Q: 什麼是模組?
A: 我們可以將一個Python程式依照功能進行分類成為多個檔案，分類後的程式檔案可以視為模組。
 模組的檔案名稱是檔案名稱加上.py作為副檔名。模組可以包含變數、函數、類別，甚至是可執行的代碼。主要目的重組程式碼，增加程式碼可讀性、重用性和維護性。

常見的Python模組分類

• 內建模組
  • math

  import math
  
  print(math.pi)
  

  PS D:\Project\practice> python hi.py
  3.141592653589793
  PS D:\Project\practice>
  

  • os

  import os
  
  print(os.getenv("LANG"))
  

  PS D:\Project\practice> python hi.py
  en_US.UTF-8
  PS D:\Project\practice>
  

  • datetime

  from datetime import date
  
  today = date.today()
  print(today)  
  

  PS D:\Project\practice> python hi.py
  2024-08-16
  PS D:\Project\practice>
  

• 第三方模組
  • requests
    用途: 簡化 HTTP 請求操作，支援 GET、POST、PUT、DELETE 等請求方法，用於與 Web 服務器進行互動。
    安裝方式: pip install requests

  PS D:\Project\practice> python -m venv .venv
  PS D:\Project\practice> cd .\.venv\Scripts\
  PS D:\Project\practice\.venv\Scripts> .\Activate.ps1
  (.venv) PS D:\Project\practice\.venv\Scripts> pip install requests
  Collecting requests
    Using cached requests-2.32.3-py3-none-any.whl.metadata (4.6 kB)
  Collecting charset-normalizer<4,>=2 (from requests)
    Using cached charset_normalizer-3.3.2-cp312-cp312-win_amd64.whl.metadata (34 kB)
  Collecting idna<4,>=2.5 (from requests)
    Using cached idna-3.7-py3-none-any.whl.metadata (9.9 kB)
  Collecting urllib3<3,>=1.21.1 (from requests)
    Using cached urllib3-2.2.2-py3-none-any.whl.metadata (6.4 kB)
  Collecting certifi>=2017.4.17 (from requests)
    Using cached certifi-2024.7.4-py3-none-any.whl.metadata (2.2 kB)
  Using cached requests-2.32.3-py3-none-any.whl (64 kB)
  Using cached certifi-2024.7.4-py3-none-any.whl (162 kB)
  Using cached charset_normalizer-3.3.2-cp312-cp312-win_amd64.whl (100 kB)
  Using cached idna-3.7-py3-none-any.whl (66 kB)
  Using cached urllib3-2.2.2-py3-none-any.whl (121 kB)
  Installing collected packages: urllib3, idna, charset-normalizer, certifi, requests
  Successfully installed certifi-2024.7.4 charset-normalizer-3.3.2 idna-3.7 requests-2.32.3 urllib3-2.2.2
  
  [notice] A new release of pip is available: 24.0 -> 24.2
  [notice] To update, run: python.exe -m pip install --upgrade pip
  (.venv) PS D:\Project\practice\.venv\Scripts> cd ..
  (.venv) PS D:\Project\practice\.venv> cd ..
  

  (.venv) PS D:\Project\practice> python hi.py        
  200
  {'userId': 1, 'id': 1, 'title': 'sunt aut facere repellat provident occaecati excepturi optio reprehenderit', 'body': 'quia et suscipit\nsuscipit recusandae consequuntur expedita et cum\nreprehenderit molestiae ut ut quas totam\nnostrum rerum est autem sunt rem eveniet architecto'}
  (.venv) PS D:\Project\practice> 
  

• 自訂模組
  • hello.py 和 hi.py 模組之間互相引用

  # hello.py
  def add(a, b):
      return a + b
  
  def hello():
      pass
  
  xyz = "9999"
  
  # 如果是單獨執行 __main__
  # 是內建變數 __name__
  print(__name__) 
  
  if __name__ == "__main__":
      if add(1, 2) == 3:
          print("ok")
      else:
          print("ng")
  

  直接印出hello.py，會執行if __name__ == "__main__":判斷式內的結果

  (.venv) PS D:\Project\practice> python hello.py
  __main__
  ok
  (.venv) PS D:\Project\practice>
  

  在hi.py中引用hello模組內的變數、函數等

  # hi.py
  from hello import add, xyz
  
  print(__name__)
  
  print(add(1, 2))
  
  print(xyz)
  

  (.venv) PS D:\Project\practice> python hi.py
  hello
  __main__
  3
  9999
  (.venv) PS D:\Project\practice> 
  

那今天就介紹到這裡，我們明天見~