Hi need help,newbie here to python

Given a range of first 10 numbers, Iterate from start number to the end number and print the sum of the current number and previous number.

def sumNum(num):
    previousNum = 0
    for i in range(num):
        sum = previousNum + i
        print("Current Number", i, "Previous Number ", previousNum," Sum: ", sum)
        previousNum = i

print(“Printing current and previous number sum in a given range(10)”)

So I do not understand why there is a need for this>>previousNum = i at the end. Please help me understand. Totally beginner to python.
Thank you :slight_smile:

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Thank you! I’ll do that .

we need to save the previous number somewhere right ? hence we do
previousNum = i
Otherwise we will forget.
An alternative way of looking at this is that, we just need to the sum of a number x and
and the number before it ,i.e, x-1 , do we not ? So we can simply loop from 1 to num and
get the sum by doing x + (x-1), i.e, a number and its previous

for i in range(1,10):
#     print(f"{i} + {i-1} = { i+(i-1) }")
    print(i + (i-1))

uncomment the line to get a detailed print.

1 Like

Thank you!! I understood :slight_smile:

Happy to help :smile: