Prevent if, elif, else chain (checking input)

If I declare these functions:

def f1(someval):
    print(someval)

def f2(someval, someval2):
    print(someval, someval2)

And if I have a dictionary that contains the functions as values:

input_dict = {"func1": f1, "func2": f2}

And I want to check if input from the user matches a key in the ditionary 'input_dict':

shell_input = 'shell~: '
for key,val in input_dict:
    if key == shell_input:
        input_dict[val](params)

How could I detect how many function parameters there are per each function being called and pass values to them, is it even possible (without declaring global variables)?

I am trying to avoid using chained if, elif, else logic in my code for example:

if shell_input == "func1":
    f1(param)
elif shell_input == "func2":
    f2(param1, param2)
#etc...

or is it okay to use chained if, elif, else logic in when checking input?