input: 
  def create_blockchain():
      """
      Creates a blockchain and adds blocks to it based on a list of transactions.
      The blockchain is initialized with a genesis block.
      
      >>> blockchain = create_blockchain()
      >>> len(blockchain)
      1
      >>> isinstance(blockchain[0], Block)
      True
      >>> print_blockchain()
      Block 0 [timestamp] No data @ [hash]
      """
  
output:     blockchain = []
      genesis_block = Block(0, "No data", "0")
      blockchain.append(genesis_block)
      return blockchain