from functools import partial

class Infix(object):
    def __init__(self, func):
        self.func = func
    def __or__(self, other):
        return self.func(other)
    def __ror__(self, other):
        return Infix(partial(self.func, other))
    def __call__(self, v1, v2):
        return self.func(v1, v2)

@Infix
def o(f,g):
    return lambda x: f(g(x))

# Example of use (composition with |o|)
#
# >> f = lambda x: x*3
# >> g = lambda x: x-15
# >> h = f |o| g