Variadic Functions in R Programming Language

Variadic Functions in Python#

Variadic functions can be called with any number of trailing arguments. For example, print is a common variadic function.

Here’s a function that will take an arbitrary number of integers as arguments.

def sum(*nums):
    print(nums, end=" ")
    total = 0

    for num in nums:
        total += num

    print(total)

def main():
    sum(1, 2)
    sum(1, 2, 3)
    nums = [1, 2, 3, 4]
    sum(*nums)

if __name__ == "__main__":
    main()

Within the function, the type of nums is equivalent to tuple. We can call len(nums), iterate over it with a loop, etc.

Variadic functions can be called in the usual way with individual arguments.

sum(1, 2)
sum(1, 2, 3)

If you already have multiple args in a list, you can apply them to a variadic function using func(*list) like this:

nums = [1, 2, 3, 4]
sum(*nums)

The expected output when running this script will be:

$ python variadic-functions.py
(1, 2) 3
(1, 2, 3) 6
(1, 2, 3, 4) 10

Another key aspect of functions in Python is their ability to form closures, which we’ll look at next.