python-magic.md

python-magic

• ahupp/python-magic: A python wrapper for libmagic #ril
  • A python wrapper for libmagic -- file type identification library
  • libmagic identifies file types by checking their HEADERs according to a predefined list of file types. This functionality is exposed to the command line by the Unix command file. 跟 Unix file 指令一樣用 libmagic。

新手上路 ?? {: #getting-started }

• Usage - ahupp/python-magic: A python wrapper for libmagic

  • 直接調用 magic.from_file()、magic.from_buffer() 即可，搭配 mime=True 可以傳回 MIME type：

    >>> import magic
    >>> magic.from_file("testdata/test.pdf")
    'PDF document, version 1.2' # 預設的行為跟 file 指令一樣
    >>> magic.from_buffer(open("testdata/test.pdf").read(1024)) # 讀進 header 就能判斷!
    'PDF document, version 1.2'
    >>> magic.from_file("testdata/test.pdf", mime=True) # 跟 file 一樣加 --mime-type 才會輸出 MIME type
    'application/pdf'
    

  • There is also a Magic class that provides more direct control, including overriding the MAGIC DATABASE FILE and turning on character encoding detection. This is not recommended for general use. In particular, it's not safe for sharing across MULTIPLE THREADS and will fail throw if this is attempted. 看似方便，但不建議使用? 不過有些 option 確實只在 magic.Magic 提供，from_file() 跟 from_buffer() 都只有 mime=False 可供調整。

    f = magic.Magic(mime=True, uncompress=True) # uncompress 會解壓縮 f.from_file('testdata/test.gz') 'text/plain'

• python-magic/magic.py at 0.4.15 · ahupp/python-magic

  • magic.Magic 的 constructor 除了 mime=False 外，還有其他選項可供調整 def __init__(self, mime=False, magic_file=None, mime_encoding=False, keep_going=False, uncompress=False)

  • mime_encoding 決定要不要額外輸出 encoding，像是 HTTP header Content-Type 後面跟的東西：

    >>> m = magic.Magic(mime=True, mime_encoding=True)
    >>> m.from_file('index.html')
    'text/html; charset=utf-8'
    

安裝設置 {: #setup }

• Installation - ahupp/python-magic: A python wrapper for libmagic
  • 用 Pip 安裝 python-magic 套件
  • macOS 要另外用 Homebrew 安裝 libmagic 套件；不過 macOS 上也有 file，為什麼還要另外裝 libmagic?

參考資料 {: #reference }

• ahupp/python-magic - GitHub
• python-magic - PyPI

相關：

• MIME Type