python_composition.py

# Note that the "# %%" thing is from Jupyter Notebooks, which should be supported by vscode by default :)
# Just run the code with the "run code" button that pops up right above the "# %%"
# %%
import functools
from typing import Callable

ComposableFunction = Callable[[float], float]


def compose(*functions: ComposableFunction) -> ComposableFunction:
    return functools.reduce(lambda f, g: lambda x: g(f(x)), functions, lambda x: x)


def add_three(x: float) -> float:
    return x + 3


def multiply_by_two(x: float) -> float:
    return x * 2


def add_n(x: float, n: float) -> float:
    return x + n


# %%
x = 12
x = add_three(x)
x = add_three(x)
x = multiply_by_two(x)
x = multiply_by_two(x)
print(f"Result: {x}")


# %%
my_func = compose(add_three, add_three, multiply_by_two, multiply_by_two)
result = my_func(12)
print(f"Result: {x}")