def xinvoke(iterable, name, *args, **kw):
'''
Feed global :term:`positional argument`\s and :term:`keyword argument`\s to
each items in `iterable`'s `name` :term:`method`.
.. note::
The original thing is returned if the return value of :term:`method`
`name` is :data:`None`.
:argument iterable: :term:`iterable`
:argument str name: method name
>>> from blade.xmap import xinvoke
>>> # invoke list.index()
>>> list(xinvoke([[5, 1, 7], [3, 2, 1]], 'index', 1))
[1, 2]
>>> # invoke list.sort() but return sorted list instead of None
>>> list(xinvoke([[5, 1, 7], [3, 2, 1]], 'sort'))
[[1, 5, 7], [1, 2, 3]]
'''
def invoke(caller, thing):
read = caller(thing)
return thing if read is None else read
return partmap(invoke, iterable, methodcaller(name, *args, **kw))
def xinvoke(iterable, name, *args, **kw):
'''
Feed global :term:`positional argument`\s and :term:`keyword argument`\s to
each items in `iterable`'s `name` :term:`method`.
.. note::
The original thing is returned if the return value of :term:`method`
`name` is :data:`None`.
:argument iterable: :term:`iterable`
:argument str name: method name
>>> from blade.xmap import xinvoke
>>> # invoke list.index()
>>> list(xinvoke([[5, 1, 7], [3, 2, 1]], 'index', 1))
[1, 2]
>>> # invoke list.sort() but return sorted list instead of None
>>> list(xinvoke([[5, 1, 7], [3, 2, 1]], 'sort'))
[[1, 5, 7], [1, 2, 3]]
'''
def invoke(caller, thing):
read = caller(thing)
return thing if read is None else read
return partmap(invoke, iterable, methodcaller(name, *args, **kw))
def xsample(iterable, n):
'''
Randomly :term:`slice` off `n` items in `iterable`.
:argument iterable: :term:`iterable`
:argument int n: sample size
:return: :term:`iterator` of items
>>> from blade.xslice import xsample
>>> list(xsample([1, 2, 3, 4, 5, 6], 3)) # doctest: +SKIP
[2, 4, 5]
'''
i1, i2 = tee(iterable)
return partmap(
lambda i, r, c, x: i(x, r(0, c)),
tee(i2, n),
islice,
randrange,
count(i1),
)
