Question

Consider the following piece of code:

def integ(fncts, propagate, stpSz):
    conditions = propagate.copy()
    iterator = 0
    for i in fncts:
        conditions[iterator] = conditions[iterator] + stpSz *  i(0)
        iterator+=1

    return conditions

Where fncts is an array of functions, like this:

 f1 = lambda x: x
 f2 = lambda x: 2*x
 fncts = (f1, f2)

Problem is, the code above works for length(fncts)>1. However, if there is only one function, it fails. How I can make sure the code can be executed if the user inputs only one function?

Answer 1

I’m assuming you mean the user inputs fncts = f? You can either require the user to always a sequence, so fncts = [f] or fncts = (f,), or check whether callable(fncts); tuples and lists are not callable.