There is problem in regex(python) I don't know How *? works, i'll post the code below

Question

Example-1

import re
data = 'astlewoieroiweru@89in.if hd'
stufff = re.findall('@([0-9]*?)', data)
print(stufff)

it prints [''] but why but there is number after the @ symbol , I know it follows non-greedy it is supposed to print ['8'] but it doesn't why? I need someone to explain me this code.

Example-2

import re
data = 'astlewoieroiweru@89in.if hd'
stufff = re.findall('@([0-9]*)', data)
print(stufff)

I know it follows greedy so it took the number after @ and stops when it sees the i, so the output is ['89']. Please explain the example-1, thank you!