Question: 
Write a function to find the last occurrence of a character in a string.


Model's Code:
def last_occurence_char(s, char):
    return s.rfind(char) if char in s else None



Sample Correct Code:
def last_occurence_char(string,char):
 flag = -1
 for i in range(len(string)):
     if(string[i] == char):
         flag = i
 if(flag == -1):
    return None
 else:
    return flag + 1


Asserts:
assert last_occurence_char("hello world",'l')==10
assert last_occurence_char("language",'g')==7
assert last_occurence_char("little",'y')==None


Tests:
Test 1 of 3: FAIL: AssertionError()

Test 546 of 974: 402/546 (73.62637362637363%): failed