Unexpected twice output

[gruntfutuk]

I'm really unclear on what you are trying to do beyond printing numbers in steps of 100 from a start point ... until you get bored and stop it. What the self referencing for loop is for, I have no idea.

What's wrong with:

from time import sleep
Rysource = 1000
large_number = 9999
 
for counter in range(Rysource, large_number, 100):
    print(counter)
    sleep(5)

---

If you really want it to go on for ever ... use a while loop, rather than a specific range in a for loop:

from time import sleep
Rysource = 1000
 
while True:
    print(Rysource)
    Rysource += 100
    sleep(5)