range countdown to zero

Question

I am taking a beginner Python class and the instructor has asked us to countdown to zero without using recursion. I am trying to use a for loop and range to do so, but he says we must include the zero.

I searched on the internet and on this website extensively but cannot find the answer to my question. Is there a way I can get range to count down and include the zero at the end when it prints?

Edit:

def countDown2(start):
#Add your code here!
    for i in range(start, 0, -1):
        print(i)

Asked By: Pashta

||

Source

Answer 1

The range() function in Python has 3 parameters: range([start], stop[, step]). If you want to count down instead of up, you can set the step to a negative number:

for i in range(5, -1, -1):
    print(i)

Output:

Answered By: user3483203

Answer 2

As another option to @chrisz’s answer, Python has a built-in reversed() function which produces an iterator in the reversed order.

start_inclusive = 4
for i in reversed(range(start_inclusive + 1)):
   print(i)

outputs

This can be sometimes easier to read, and for a well-written iterator (e.g. built-in range function), the performance should be the same.

Answered By: Wehrdo

Answer 3

In the below code n_range doesn’t need to be told to count up or down, it can just tell if the numbers ascend or descend through the power of math. A positive value divided by it’s negative equivalent will output a -1 otherwise it outputs a 1.

def n_range(start, stop):
    return range(start, stop, int(abs(stop-start)/(stop-start)))

An input of 5, -1 will output

Answered By: Jamie Jenson

range countdown to zero

Question:

Answers: