What is the Python bin() function?

#  Integer 15 represented in decimal
decimal = 15
#  Integer 15 represented in hexadecimal
hexadecimal = 0xf
#  Integer 15 represented in octal
octal = 0o17
print("Binary representation", bin(decimal))
print("Binary representation", bin(hexadecimal))
print("Binary representation", bin(octal))

class Total:
  def __init__(self, price, quantity):
    self.price = price
    self.quantity = quantity
  # Implement __index()__ to return an integer
  def __index__(self):
    return self.price * self.quantity
# supply integral values to the constructor only
total_price = Total(1, 4)
print("Binary representation", bin(total_price))