Python Recursion: Range

Question

I need to define a function called rec_range(n) which takes a natural number and returns a TUPLE of numbers up to the number n.

i.e. rec_range(5) returns (0,1,2,3,4)

Answer 1

I would write it as follows:

def rec_range(n):
    if n < 1:
        return ()
    else:
        return rec_range(n - 1) + (n - 1,)

print(rec_range(4)) # prints (0, 1, 2, 3)

This can also handle negative arguments.