def main(self):
# initiate block chain with num of zero that we want for proof of work
num_of_zero = 5
block_chain = BlockChain(num_of_zero)
miner = Miner(block_chain.hash_processor, block_chain.num_of_zero)
block_count = 0
while block_count < 5:
transaction_list = []
# generate random transaction
num_of_transaction = randint(1, 4)
for i in range(num_of_transaction):
from_id = randint(1, 100)
to_id = randint(1, 100)
amount = randint(200, 1000)
transaction = Transaction(from_id, to_id, amount)
transaction_list.append(transaction)
# ask miner to get new block to wrap transactions
# miner will do brute force in order to get the appropriate hash
block = miner.get_new_block(transaction_list,
block_chain.get_prev_hash())
# add to block_chain
# block chain will verify the block
block_chain.add_block(block)
# print calculated hash value to user
# to make sure right number of zero in the hash
hash_val = block_chain.hash_processor.calculate_hash(
block.get_hash_num())
print("block number %d" % (block_count + 1, ))
print("hash value : " + str(hash_val))
print("generated block : " + str(block))
print()
block_count += 1
# check mutation validation
# first should be valid
print(block_chain.check_is_valid())
# save current value and change the amount to new one
prev_amount = block_chain.blocks[1].transaction_list[0].amount
block_chain.blocks[1].transaction_list[0].amount = 100800
# check validity again, should be false
print(block_chain.check_is_valid())
# change it to original value
# should be valid again
block_chain.blocks[1].transaction_list[0].amount = prev_amount
print(block_chain.check_is_valid())
