I found this practice today:
Detect whether a check number is valid or not. The check number must have 10 digits, can not have 2 or more zeros followed, nor three or more digits other than zero followed
I've able to complete the first part with this code:
num_chk=input('Enter chk number: ')
if (len(num_chk) == 10):
Let's say your check number is the variable
check_number and it is 12300.
check_number = 12300 convert it to a string: str_check_num = str(check_number) # str_check_num now equals "12300" a a string has_00 = "00" in str_check_num # Returns True if "00" is in str_check_num. in this case it is.