input: from typing import List
  
  def create_blockchain(transactions: List[str]) -> List[dict]:
      """Build a simple blockchain system in Python. Each block contains an index, timestamp, data, and the hash of the previous block. The function should create a blockchain starting with a genesis block and add blocks for each transaction provided.
      >>> create_blockchain(["Transaction 1", "Transaction 2"])
      [{'index': 0, 'timestamp': '<timestamp>', 'data': 'Genesis Block', 'previous_hash': '0', 'hash': '<hash>'}, {'index': 1, 'timestamp': '<timestamp>', 'data': 'Transaction 1', 'previous_hash': '<hash>', 'hash': '<hash>'}, {'index': 2, 'timestamp': '<timestamp>', 'data': 'Transaction 2', 'previous_hash': '<hash>', 'hash': '<hash>'}]
      """
output:     import hashlib
      import time
  
      def calculate_hash(index, previous_hash, timestamp, data):
          value = str(index) + previous_hash + str(timestamp) + data
          return hashlib.sha256(value.encode()).hexdigest()
  
      blockchain = []
      genesis_block = {
          'index': 0,
          'timestamp': time.time(),
          'data': 'Genesis Block',
          'previous_hash': '0',
          'hash': calculate_hash(0, '0', time.time(), 'Genesis Block')
      }
      blockchain.append(genesis_block)
  
      for i, transaction in enumerate(transactions):
          block = {
              'index': i + 1,
              'timestamp': time.time(),
              'data': transaction,
              'previous_hash': blockchain[-1]['hash'],
              'hash': calculate_hash(i + 1, blockchain[-1]['hash'], time.time(), transaction)
          }
          blockchain.append(block)
  
      return blockchain