snippet1.py

# A block is stored as a tuple of
# (parent_hash, transactions, hash_itself)

def get_parent_hash(block):
    return block[0]


def get_transactions(block):
    return block[1]


def get_hash_itself(block):
    return block[2]

# function to create a block in a blockchain
def create_block(transactions, parent_hash):
    hash_itself = hash((transactions, parent_hash))
    return (parent_hash, transactions, hash_itself)


# function to create the genesis block
def create_genesis_block(transactions):
    return create_block(transactions, 0)


# we create our genesis block
genesis_block = create_genesis_block("X paid $100 to Y")

# print the hash of the genesis_block
genesis_block_hash = get_hash_itself(genesis_block)
print "genesis_block_hash:", genesis_block_hash

# create another block
block1 = create_block("Y paid $20 to Z, X paid $10 to P", genesis_block_hash)

# print the hash of block1
block1_hash = get_hash_itself(block1)
print "block1_hash:", block1_hash