knife 0.5.0

Pythonic remix of underscore.js: Things go in. Things get knifed. Things go out.

knife is a powerful Python multitool loosely inspired by underscore.js but remixed for maximum pythonicity.

knife concentrates power normally found dispersed across the Python universe in one convenient shrink-wrapped package.

Vitals

knife’s documentation is found at http://readthedocs.org/docs/knife/en/latest/ or http://packages.python.org/knife/

knife works with Python 2.6, 2.7, and 3.2.

Installation

knife is installed with pip:

$ pip install knife
[... possibly exciting stuff happening ...]
Successfully installed knife

Or easy_install:

$ easy_install knife
[... possibly exciting stuff happening ...]
Finished processing dependencies for knife

knife can also be downloaded from http://pypi.python.org/knife and installed old school:

$ python setup.py install
[... possibly exciting stuff happening ...]
Finished processing dependencies for knife

Development

• Public repository: https://bitbucket.org/lcrees/knife.

• Mirror: https://github.com/kwarterthieves/knife/

• Issue tracker: https://bitbucket.org/lcrees/knife/issues

• License: BSD license

knife in 3 seconds

Things go in:

>>> gauntlet = __(5, 4, 3, 2, 1)

Things get knifed:

>>> gauntlet.initial().rest().slice(1, 2).last()

Things come out:

>>> gauntlet.get()
3

Slightly More

knife has over 40 methods that can be chained.

contrived example:

>>> from knife import __
>>> __(5, 4, 3, 2, 1).initial().rest().slice(1, 2).last().get()
3

Or used object-oriented style.

contrived example:

>>> from knife import knife
>>> oo = knife(('a', 1), ('b', 2), ('c', 3))
>>> oo.wrap(dict)
>>> oo.map()
>>> oo.get()
{'a': 1, 'b': 2, 'c': 3}

knife knives can roll the data it is knifing back to the results of immediately preceding steps, a baseline snapshot, or even the original arguments.

contrived example:

>>> undone = __(1, 2, 3).prepend(1, 2, 3, 4, 5, 6)
>>> undone.peek()
[1, 2, 3, 4, 5, 6, 1, 2, 3]
>>> undone.append(1).undo().peek()
[1, 2, 3, 4, 5, 6, 1, 2, 3]
>>> undone.append(1, 2).undo(2).peek()
[1, 2, 3, 4, 5, 6, 1, 2, 3, 1]
undone.snapshot().append(1, 2).baseline().peek()
[1, 2, 3, 4, 5, 6, 1, 2, 3, 1]
undone.original().peek()
[1, 2, 3]
>>> one.original().minmax().pipe(two).merge().back().max().get()
1000
>>> one.original().minmax().pipe(two).merge().back().sum().get()
1002

knife knives come in two flavors: active and lazy. Active knives evaluate the result of each method immediately it’s called. Calling the same method with a lazy knife only generate results when they are iterated over or knife.lazy.lazyknife.get is called to get results.

knife.lazy.lazyknife combines all knife methods into one knife class:

>>> from knife import lazyknife

It can be imported under its dunderscore (knife.__) alias.

>>> from knife import __

knife.active.activeknife combines every knife method in one combo knife class:

>>> from knife import activeknife

It can be imported under its knife.knife alias:

>>> from knife import knife

knife’s methods also come in focused classes group knife methods with related functionality that can be chained together into pipelines.

contrived example:

>>> from knife.active import mathknife, reduceknife
>>> one = mathknife(10, 5, 100, 2, 1000)
>>> two = reduceknife()
>>> one.minmax().pipe(two).merge().back().min().get()
2