A module to parse metadata out of documents
MetadataParser is a python module for pulling metadata out of web documents.
It requires BeautifulSoup , and was largely based on Erik River’s opengraph module ( https://github.com/erikriver/opengraph ).
I needed something more aggressive than Erik’s module , so had to fork.
pip install metadata_parser
- it pulls as much metadata out of a document as possible
- you can set a ‘strategy’ for finding metadata ( ie, only accept opengraph or page attributes )
- This requires BeautifulSoup 4.
- For speed, it will instantiate a BeautifulSoup parser with lxml , and fall back to ‘none’ (the internal pure python) if it can’t load lxml
- It is HIGHLY recommended that you install lxml for usage. It is considerably faster. Considerably faster. *
You should also use a very recent version of lxml. I’ve had problems with segfaults on some versions < 2.3.x ; i would suggest using the most recent 3.x if possible.
- The default ‘strategy’ is to look in this order:
- og,dc,meta,page og = OpenGraph dc = DublinCore meta = metadata page = page elements
You can specify a strategy as a comma-separated list of the above.
- The only 2 page elements currently supported are:
- <title>VALUE</title> -> metadata[‘page’][‘title’] <link rel=”canonical” href=”VALUE”> -> metadata[‘page’][‘link’]
The MetadataParser object also wraps some convenience functions , which can be used otherwise , that are designed to turn alleged urls into well formed urls.
For example, you may pull a page:
and that file indicates a canonical url which is simple “/file.html”.
This package will try to ‘remount’ the canonical url to the absolute url of “http://www.example.com/file.html” . It will return None if the end result is not a valid url.
This all happens under-the-hood, and is honestly really useful when dealing with indexers and spiders.
From an URL
>>> import metadata_parser >>> page = metadata_parser.MetadataParser(url="http://www.cnn.com") >>> print page.metadata >>> print page.get_field('title') >>> print page.get_field('title',strategy='og') >>> print page.get_field('title',strategy='page,og,dc')
>>> HTML = """<here>""" >>> page = metadata_parser.MetadataParser(html=HTML) >>> print page.metadata >>> print page.get_field('title') >>> print page.get_field('title',strategy='og') >>> print page.get_field('title',strategy='page,og,dc')