Examples

Pipe data through unix-like/elixir-like pipes:

>>> from pelper import pipe
>>> pipe("some datat, some data", set, (sorted, {"reverse": True}))
['t', 's', 'o', 'm', 'e', 'd', 'a', ',', ' ']

Pelper offers p-functions, i.e., functions where the first argument is data. There is pmap (like map, but works with pipel):

>>> from pelper import pipe, pmap
>>> pipe(
...     range(5),
...     (pmap, lambda x: x*x),
...     list)
[0, 1, 4, 9, 16]

…and also pfilter:

>>> from pelper import pipe, pfilter
>>> pipe(
...     range(5),
...     (pfilter, lambda x: x > 2),
...     list)
[3, 4]

Take n elements from iterables (useful if you can’t use the square bracket notation, e.g., if you’re using pipe)

>>> from pelper import take
>>> take("hello world", 5)
['h', 'e', 'l', 'l', 'o']

Take the n-th elements from iterables (useful if you can’t use the square bracket notation, e.g., if you’re using pipe)

>>> from pelper import nth
>>> nth(range(5), 2)
2

Flatten arbitrarily nested lists:

>>> from pelper import flatten
>>> flatten([1, [2, 2, [3, 3]]])
[1, 2, 2, 3, 3]

Measure the duration of a function:

>>> from pelper import print_duration
>>> @print_duration()
...  def f(n): pass

Measure the duration of a context:

>>> from pelper import print_duration
>>> with print_duration():
...     range(4)

Ignore exceptions:

>>> from pelper import ignored
>>> with ignored(OSError):
...     raise OSError()  # this is ignored

Cache already computed results of functions:

>>> from pelper import cache
>>> @cache
>>> def fib(n):
...     return 1 if n < 2 else fib(n-1) + fib(n-2)
>>> f(500)  # this would run for quite a wile without the cache decorator

Easier printing and formating:

>>> from pelper import printf
>>> printf("Hello {name}, I'm {something}", name="Alan", something="world")
Hello Alan, I'm world

Installation

pelper is only one file and has no dependencies. You can simply drop pelper.py into your project and use it.

Or install it from pypi by running:

pip install pelper

Or install it from source by running:

pip install .

Development

Use virtualenv for working on pelper. Install the dev requrirements via:

pip install -e requirements-dev.txt

tox

tox -e py27,py34,py35

py.test

cd docs
sphinx html