I am trying to test if the decimal representation of a certain number contains the digit 9 at least twice, so I decided to do something like that:
i=98759102
Your problem is here:
string.replace(9, '', 1)
You need to make 9
a string literal, rather than an integer:
string.replace('9', '', 1)
As for a better way to count the occurrences of 9
in your string, use str.count():
>>> i = 98759102
>>> string = str(i)
>>>
>>> if string.count('9') > 2:
print('yes')
else:
print('no')
no
>>>
You need quotes around the nine.