The Reciprocals of Primes

prime_reciprocals.py

def repeating_digit(num: int) -> int:
   """
   code inspired by 
   The Reciprocals of Primes - Numberphile
   on youtube: https://www.youtube.com/watch?v=DmfxIhmGPP4&ab_channel=Numberphile
   Parameter
   
   num: a prime number

   returns: The number of repeating digits of reciprocal of a prime number
   """
   digits = len(str(num))
   remainders = set()
   remainder = 1
   count = 0
   while remainder not in remainders and count < num:
     count += 1
     remainders.add(remainder)
     remainder = (remainder * 10 ** digits) % num
   return count