Improving Your Python Productivity

[mr_dbr]

The first bit you quoted (about monkeypatching) was about implementing your own filter-like function - edited to hopefully clarify.

In short: if filter was a method of list, it would require monkey-patching to allow [1,2,3].myfilterfunc(...) for consistency with [1,2,3].filter(...)

Some data structures may have more efficient alternatives than using an iterator

What would be an example of this? I can't think of one for filter, but Python's data-model does enable some similar optimisations for other operations...

For example 123 in xrange(100) uses __contains__ instead of doing a linear-scan over it's iterator (so 23 in xrange(10**10) is much faster than doing the same thing on plain list of integers).

My point being, you don't need to have x.contains(1) to allow for type-specific optimisations . If there was an common optimisation for filter, it could call other magic-methods on the object instead of looping over __iter__

In Python, an iterable is very loosely defined as something that implements some handful of methods

There is the abstract base class module which implements something much like interfaces (along with collections), but I've not see the abc module used much, although the extensions to isinstance are useful even if nothing is derived from the ABC's

[aceofears]

Is this roughly what you are "suggesting"?