Examples

F and `_` (singleton)

from placeholder import _

_.real

F(operator.attrgetter('real'))

nums = (0 + 2j), (1 + 1j), (2 + 0j)
min(nums, key=_.real)

2j

min(nums, key=_.imag)

(2+0j)

_[0]

F(operator.itemgetter(0))

pairs = "ac", "bb", "ca"
min(pairs, key=_[0])

'ac'

min(pairs, key=_[-1])

'ca'

import itertools

list(itertools.accumulate(range(1, 6), _ * _))

[1, 2, 6, 24, 120]

list(itertools.filterfalse(_ % 2, range(10)))

[0, 2, 4, 6, 8]

list(filter(_ % 2 == 0, range(10)))

[0, 2, 4, 6, 8]

list(filter(abs(_) < 1, [-1, 0, 1]))

[0]

Support for attrgetter(*), itemgetter(*), and methodcaller.

from placeholder import m

m("real", "imag")

F(operator.attrgetter('real', 'imag'))

m[0, -1]

F(operator.itemgetter(0, -1))

m.split("-")

operator.methodcaller('split', '-')