“Perfect” Libraries

Sometimes you use a third party library and the interface is so well designed it’s just effortless. Something that would have been gnarly and murky becomes simple. The kind of library that gets ported to multiple languages because everyone wants access to it.

One slightly obscure example is feedparser, (originally) Mark Pilgrim’s python2 library for reading Atom and RSS feeds. Hiding all this nonsense:

behind a simple interface.

import feedparser 
d = feedparser.parse('http://www.reddit.com/r/python/.rss') 
print(d['feed']['title'])
>>> Python
print d.feed.subtitle 
>>> news about the dynamic, interpreted, interactive, object-oriented, extensible programming language Python 
print d.headers           
>>>  {'content-length': '5393', 'content-encoding': 'gzip', 'vary': 'accept-encoding', 'server': "'; DROP TABLE servertypes; --", 'connection': 'close', 'date': 'Mon, 14 Oct 2013 09:13:34 GMT', 'content-type': 'text/xml; charset=UTF-8'}

Another library that has the same simplicity is Mustache logic-less templates. This one has been ported to literally dozens of languages. Every template I ever worked on was kind of a mess until I found Mustache. It’s actually the restrictions here that make it sing.

Hello {{name}} 
You have just won {{value}} dollars! 
{{#in_ca}} Well, {{taxed_value}} dollars, after taxes. {{/in_ca}}

Some other examples:

• web.py – Dead simple web framework
• BeautifulSoup – HTML/XML parser
• requests – Python library for HTTP
• humps – Underscore-to-camelCase converter (and vice versa) for strings and object keys in JavaScript (has been ported to Python as pyhumps).
• Markdown – Text format with HTML representation that has taken over the web due to its simplicity and usefulness compared to actual HTML

Do you know any “perfect” libraries?