Functional Programming

extepy provides APIs for argument reorganizing and execution.

Function Execution

extepy.call(f, *args, **kwargs)

Call a callable with positional arguments and keyword arguments.

Parameters:

• f – Callable object.

• *args – Positional arguments.

• **kwargs – Keyword arguments.

Returns:

Result of the callable.

Examples

>>> call(sum, [2, 3, 6])
11

Reorganize Arguments

extepy provides APIs for refactoring arguments of callable functions. They can be used as decorators of functions.

extepy.pack(f)

Merge all positional arguments of a function to a single tuple argument

Parameters:

f (callable)

Return type:

callable

Examples

Apply on a function.

>>> packed = pack(isinstance)
>>> packed([1.0, float])
True

Use as a decorator.

>>> import math
>>> @pack
... def g(*args):
...    return sum(arg + 1 for arg in args)
>>> g([1, 2, 3])
9

extepy.unpack(f)

Replace a single tuple/list argument to many positional arguments.

Parameters:

f (callable)

Return type:

callable

Examples

Apply on a function.

>>> unpacked = unpack(all)
>>> unpacked(True, True, True)
True

Use as decorator.

>>> @unpack
... def g(values):
...    return max(values) - min(values)
>>> g(1, 2, 3)
2

Function Composition

extepy.repeat(n=1)

Repeat a callable n times.

Parameters:

n (int) – Number of times to repeat.

Returns:

a callable that swaps a callable so that it is called n times.

Return type:

Callable[callable, callable]

Examples

Apply on a function.

>>> repeated = repeat(n=2)(abs)
>>> repeated(-3)
3

Use as a decorator.

>>> @repeat(n=2)
... def g(a):
...     return a + 1
>>> g(1)
3

extepy.skewer(*callables)

Composite multiple callables into one callable.

Parameters:

*callables (callable)

Returns:

A callable that calls all callables in order.

Return type:

callable

Examples

>>> def minmax(x, y):
...     return min(x, y), max(x, y)
>>> def mul(x, y):
...     return x * y
>>> skewered = skewer(minmax, mul)
>>> skewered(5, 3)
15