A function composition operator in Python

Question

In this question I asked about a function composition operator in Python. @Philip Tzou offered the following code, which does the job.

import functools

class Co         


        

Answer 1

I am actually unwilling to provide this answer. But you should know in certain circumstance you can use a dot "." notation even it is a primary. This solution only works for functions that can be access from globals():

import functools

class Composable:

    def __init__(self, func):
        self.func = func
        functools.update_wrapper(self, func)

    def __getattr__(self, othername):
        other = globals()[othername]
        return lambda *args, **kw: self.func(other.func(*args, **kw))

    def __call__(self, *args, **kw):
        return self.func(*args, **kw)

To test:

@Composable
def add1(x):
    return x + 1

@Composable
def add2(x):
    return x + 2

print((add1.add2)(5))
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