Pythonで関数合成と適用的な ref: https://qiita.com/hatchinee/items/ab208f0ce596964c1a31

file0.txt

def compose(f_t_u, f_u_r):
    '''
    :type f_t_u: t -> u
    :type f_u_r: u -> r
    :rtype: t -> r

    >>> comp(lambda a: a + 'oppai', lambda b: b + 'hoge')('')
    'oppaihoge'
    >>> comp(comp(lambda a: a+'oppai', lambda b: b+ 'hoge'), lambda x: '[' + x + ']')('')
    '[oppaihoge]'
    '''
    return lambda t: f_u_r(f_t_u(t))

file1.txt

class infix(object):
    def __init__(self, function):
        self.function = function

    def __ror__(self, other):
        self.left = other
        return self

    def __or__(self, other):
        return self.function(self.left, other)

    def __call__(self, value1, value2):
        return self.function(value1, value2)

@infix
def c(f_t_u, f_u_r): return lambda t: f_u_r(f_t_u(t))

file2.txt

(str.upper |c| sorted |c| set)('abcdeabc')
# > set(['A', 'C', 'B', 'E', 'D'])

file3.txt

class Ap(object):
    def __init__(self, val):
        self.val=val
    def __rshift__(self, func):
        return func(self.val)

file4.txt

Ap('abcdeabc') >> (str.upper |c| sorted |c| set)
# > set(['A', 'C', 'B', 'E', 'D'])

file5.txt

class _Ap(object):
    def __rlshift__(self, other):
        self.value = other
        return self

    def __rshift__(self, other):
        return other(self.value)
Ap = _Ap()
a = Ap

file6.txt

'abcdacb' <<a>> (str.upper |c| sorted)
#> ['A', 'A', 'B', 'B', 'C', 'C', 'D']