How can I merge two functions in one function?

August 13, 2022

Let there are some codes like

def f(a, b):
    # some code (no return)

def g(c, d, e):
    # some code (no return)

Then, I want to make a function "merge_functions" which

h = merge_functions(f, g)

works same with:

def h(a, b, c, d, e):
    f(a, b)
    g(c, d, e)

There could be more or fewer parameters in f and g, and I want to keep the name of the parameters the same.

There is no default value in any parameters.

I have tried:

from inspect import signature

getarg = lambda func: list(dict(signature(func).parameters).keys())
to_arg_form = lambda tup: ', '.join(tup)
def merge_functions(f, g):
    fl = getarg(f)
    gl = getarg(g)
    result = eval(f"lambda {to_arg_form(fl+gl)}:{f.__name__}({to_arg_form(fl)}) and False or {g.__name__}({to_arg_form(gl)})")
    return result

However, I could only use this function in the same file, not as a module.
How can I make the function that can also be used as a module?

>Solution :

You can try something like this code which creates a third function which you can use everywhere:

def f1(x1, x2, **args):
    print(f"{x1} {x2}")

def f2(x1, x3, x4, **args):
    print(f"{x1} {x3} {x4}")

def merge(f1, f2):
    return lambda **args: (f1(**args), f2(**args))

f3 = merge(f1, f2)

f3(x1=1, x2=2, x3=3, x4=4)