input: 
  def convert_to_binary(num):
      """
      Generate a code in Python to convert a number into binary format.
      >>> convert_to_binary(0)
      0
      >>> convert_to_binary(10)
      1010
      >>> convert_to_binary(7)
      111
      """
      if num == 0:
          return 0
      
      binary = ''
      
      while num != 0:
          remainder = num % 2
          binary = str(remainder) + binary
          num = num // 2
      
      return binary
  
output:     if num == 0:
          return '0'