made a list of prime values in python from 0 to n and checked if sum of two primes is equal to n and first value less than or equal to second value then converted them to string and appended values to partition list ... sampe tests are successful when submitting got the error 'NameError: name 'primes' is not defined' for large integers.......any help please

getting error:
Traceback:
in
in alphabet_position
IndexError: list assignment index out of range