new_contents: '''
  A collection of utility methods for common operations in Project Euler problems
  '''
  
  from math import sqrt, floor
  
  
  def is_prime(x):
      if x < 2:
          return False
      i = 2
      while i < int(floor(sqrt(x)))+1:
          if x % i == 0:
              return False
          i += 1
      return True
  
  
  def erathos(n):
      '''
      Create an Erathostenes sieve for prime numbers up to n
      '''
      l = list(range(n))
      l[1] = 0
      sqrt = int(round(n**0.5))
      for i in range(2, sqrt + 1):
          if l[i]:
              l[i * i: n: i] = [0] * len(range(i * i, n, i))
      return list(filter(None, l))
  
  
  def is_pandigital(x):
      digits = list(str(x))
      return ''.join(sorted(digits)) == '123456789'
  
subject: move common methods in utility file