Simon Willison’s Weblog

Python and micropayments

Fredrik Lundh has started posting his book The Standard Python Library online, in response to O’Reilly’s decision not to publish a second edition of the book. I’d never read it before, but having sampled the first two chapters I’m hooked. It works a bit like a “cookbook”, with a plethora of code samples explained in detail accompanied by tips and tricks relating to the language. The Lazy Import class, which loads a module only when an attribute of the module is called for the first time, is a classic example:

class LazyImport:
    def __init__(self, module_name):
        self.module_name = module_name
        self.module = None
    def __getattr__(self, name):
        if self.module is None:
            self.module = __import__(self.module_name)
        return getattr(self.module, name)

string = LazyImport("string")
print string.lowercase

Frederick plans to release a chapter every Friday until the whole book has been posted. Alernatively, you can buy the whole 1999 edition from him as a PDF file for the princely sum of $5.00, which works out at £3.18 in GBP via PayPal.

I think that was my first ever micropayment.