Blockchain Explained: Supply Chain Example with Python Tutorial 

can you please share your github or code for the same video

Can you explain this in more detail when you mean privacy enhancing block chains? Block chains aren’t meant to be private persay, only secure and immutable. Blockchain like ETH and BTC have transactions available on the open web by design.

Great suggestion

@@SATSifaction That would be awesome. Do you have the code btw? If not I might be able to type it out for others too. Thank you.

from hashlib import sha256 import json from datetime import datetime class Block: def __init__(self, index, previous_hash, current_transactions, timestamp, nonce): self.index = index self.previous_hash = previous_hash self.current_transactions = current_transactions self.timestamp = timestamp self.nonce = nonce self.hash = self.compute_hash() def compute_hash(self): block_string = json.dumps(self.__dict__, sort_keys=True) first_hash = sha256(block_string.encode()).hexdigest() second_hash = sha256(first_hash.encode()).hexdigest() return second_hash def __str__(self): return str(self.__dict__) class BlockChain: def __init__(self): self.chain = [] self.transactions = [] self.genesis_block() def __str__(self): return str(self.__dict__) def genesis_block(self): genesis_block = Block('Genesis', 0x0, [3, 4, 5, 6, 7], 'datetime.now().timestamp()', 0) genesis_block.hash = genesis_block.compute_hash() self.chain.append(genesis_block.hash) self.transactions.append(str(genesis_block.__dict__)) def getLastBlock(self): return self.chain[-1] def proof_of_work(self, block: Block): difficulty = 1 block.nonce = 0 computed_hash = block.compute_hash() while not (computed_hash.endswith('0'*difficulty) and ('55'*difficulty) in computed_hash): block.nonce += 1 computed_hash = block.compute_hash() return computed_hash def add(self, data): block = Block(len(self.chain), self.chain[-1], data, 'datetime.now().timestamp()', 0) block.hash = self.proof_of_work(block) self.chain.append(block.hash) self.transactions.append(block.__dict__) return json.loads(str(block.__dict__).replace('\'', '\"')) def getTransactions(self, id): labels = ['Manufacturer', 'Transportation', 'Retailer'] while True: try: if id == 'all': for i in range(len(self.transactions)-1): print('{}: {} '.format(labels[i], self.transactions[i+1])) break elif type(id) == int: print(self.transactions[id]) break except Exception as e: print(e) def main(): manufacturer = { 'transactions': [ { 'timestamp': datetime.now().timestamp(), 'product_id': 1, 'product_serial': 50001000, 'name': 'cotton pants', 'from': 'Manufacturer X', 'to': 'Transportation X', 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002000, 'name': 'cotton shirt', 'from': 'Manufacturer X', 'to': 'Transportation X', 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002001, 'name': 'cotton shirt', 'from': 'Manufacturer X', 'to': 'Transportation X', 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' } ] } transportation = { 'transactions': [ { 'timestamp': datetime.now().timestamp(), 'product_id': 1, 'product_serial': 50001000, 'name': 'cotton pants', 'from': 'Transportation X', 'to': 'Retailer X', 'shipping_id': 100, 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002000, 'name': 'cotton shirt', 'from': 'Transportation X', 'to': 'Retailer X', 'shipping_id': 101, 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002001, 'name': 'cotton shirt', 'from': 'Transportation X', 'to': 'Retailer X', 'shipping_id': 102, 'message': 'Product damaged', 'digital signiture': 'retailer review', 'flagged': 'Y' } ] } retailer = { 'transactions': [ { 'timestamp': datetime.now().timestamp(), 'product_id': 1, 'product_serial': 50001000, 'name': 'cotton pants', 'from': 'Retailer X', 'to': 'Retail Shelf', 'receiving_id': 400, 'message': 'This product is in good order, Received', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002000, 'name': 'cotton shirt', 'from': 'Retailer X', 'to': 'Retail Shelf', 'receiving_id': 400, 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002001, 'name': 'cotton shirt', 'from': 'Retailer X', 'to': 'RTV', # Return to Vendor 'receiving_id': 401, 'message': 'Box Damaged', 'digital signiture': 'rejected', 'flagged': 'Y' } ] } B = BlockChain() a = B.add(manufacturer) b = B.add(transportation) c = B.add(retailer) B.getTransactions('all') if __name__ == '__main__': main()

hi its in the following article i wrote for the startup --> medium.com/swlh/blockchain-simplified-and-explained-79c5844e318f

@@SATSifaction is not

You’re welcome. Thanks for watching. Please consider subscribing if you haven’t already

from hashlib import sha256 import json from datetime import datetime class Block: def __init__(self, index, previous_hash, current_transactions, timestamp, nonce): self.index = index self.previous_hash = previous_hash self.current_transactions = current_transactions self.timestamp = timestamp self.nonce = nonce self.hash = self.compute_hash() def compute_hash(self): block_string = json.dumps(self.__dict__, sort_keys=True) first_hash = sha256(block_string.encode()).hexdigest() second_hash = sha256(first_hash.encode()).hexdigest() return second_hash def __str__(self): return str(self.__dict__) class BlockChain: def __init__(self): self.chain = [] self.transactions = [] self.genesis_block() def __str__(self): return str(self.__dict__) def genesis_block(self): genesis_block = Block('Genesis', 0x0, [3, 4, 5, 6, 7], 'datetime.now().timestamp()', 0) genesis_block.hash = genesis_block.compute_hash() self.chain.append(genesis_block.hash) self.transactions.append(str(genesis_block.__dict__)) def getLastBlock(self): return self.chain[-1] def proof_of_work(self, block: Block): difficulty = 1 block.nonce = 0 computed_hash = block.compute_hash() while not (computed_hash.endswith('0'*difficulty) and ('55'*difficulty) in computed_hash): block.nonce += 1 computed_hash = block.compute_hash() return computed_hash def add(self, data): block = Block(len(self.chain), self.chain[-1], data, 'datetime.now().timestamp()', 0) block.hash = self.proof_of_work(block) self.chain.append(block.hash) self.transactions.append(block.__dict__) return json.loads(str(block.__dict__).replace('\'', '\"')) def getTransactions(self, id): labels = ['Manufacturer', 'Transportation', 'Retailer'] while True: try: if id == 'all': for i in range(len(self.transactions)-1): print('{}: {} '.format(labels[i], self.transactions[i+1])) break elif type(id) == int: print(self.transactions[id]) break except Exception as e: print(e) def main(): manufacturer = { 'transactions': [ { 'timestamp': datetime.now().timestamp(), 'product_id': 1, 'product_serial': 50001000, 'name': 'cotton pants', 'from': 'Manufacturer X', 'to': 'Transportation X', 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002000, 'name': 'cotton shirt', 'from': 'Manufacturer X', 'to': 'Transportation X', 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002001, 'name': 'cotton shirt', 'from': 'Manufacturer X', 'to': 'Transportation X', 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' } ] } transportation = { 'transactions': [ { 'timestamp': datetime.now().timestamp(), 'product_id': 1, 'product_serial': 50001000, 'name': 'cotton pants', 'from': 'Transportation X', 'to': 'Retailer X', 'shipping_id': 100, 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002000, 'name': 'cotton shirt', 'from': 'Transportation X', 'to': 'Retailer X', 'shipping_id': 101, 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002001, 'name': 'cotton shirt', 'from': 'Transportation X', 'to': 'Retailer X', 'shipping_id': 102, 'message': 'Product damaged', 'digital signiture': 'retailer review', 'flagged': 'Y' } ] } retailer = { 'transactions': [ { 'timestamp': datetime.now().timestamp(), 'product_id': 1, 'product_serial': 50001000, 'name': 'cotton pants', 'from': 'Retailer X', 'to': 'Retail Shelf', 'receiving_id': 400, 'message': 'This product is in good order, Received', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002000, 'name': 'cotton shirt', 'from': 'Retailer X', 'to': 'Retail Shelf', 'receiving_id': 400, 'message': 'This product is in good order', 'digital signiture': 'approved', 'flagged': 'N' }, { 'timestamp': datetime.now().timestamp(), 'product_id': 2, 'product_serial': 50002001, 'name': 'cotton shirt', 'from': 'Retailer X', 'to': 'RTV', # Return to Vendor 'receiving_id': 401, 'message': 'Box Damaged', 'digital signiture': 'rejected', 'flagged': 'Y' } ] } B = BlockChain() a = B.add(manufacturer) b = B.add(transportation) c = B.add(retailer) B.getTransactions('all') if __name__ == '__main__': main()

@@imranrajjad7028 it still doesn't run please help