Simple Python Blockchain Implementation - Simplecoin part 4

Posted by Suraj Singh on May 24, 2018 · 85 mins read
hii readers,



Sorry For my late blog posts, Actually I'm still busy in studying blockchain and bitcoin concepts. So, Today, again I am going to share with you a new python script where I tried to add some more features in previous simple blockchain based ledger python script.


For the Previous post

Part 1: check here
Part 2: check here
Part 3:  check here

Note

  • Tutorials And Reference For This Script Coming Soon...
  • Sorry For Less Comments And Bad Coding Styles.

Actually, Guys, I'm Still Busy In Developing This Script To Make More Advance, Adding More Features In It.
So, I'm Open For Suggestions Comments And Contributions.

Some Key Features Of This Script.

  • Transactions Feature Supported
  • Transaction Address Supported
  • Double Spend Detection Supported
  • Strict Transaction Validations Supported
  • Simple wallet Supported
  • Miner Automatic Reward Receiving Supported
  • Transactions Merkle Data hashing Algorithm Supported
  • Block Hashing Verification Supported
  • Previous block hash verification supported
  • Transaction Signature Verification
  • Proof Of Work Supported (hashcash)
  • Proof Of Work Verification Supported
  • Invalid Transaction Detection Functions
  • Balance Finding Supported
  • All Transaction Extraction Supported
  • Automatic Key Handling Supported
  • Input Transaction Verification Available
  • Easy Signature Verification Handling
  • Database created In Json To Make It More Simple To Understand
  • Python Object Orient Programming Basic Support


Requirements

  • PyCrypto Module
  • Python2.7
  • Currently Tested On Ubuntu Only

For More Details. Refer To my Github Repo. Check Here


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#!/usr/bin/python

__author__='''
Suraj Singh bisht
surajsinghbisht054@gmail.com
www.bitforestinfo.com
github.com/surajsinghbisht054


'''


# coding: utf-8

# In[100]:


import json
import os
from hashlib import sha256
from Crypto.PublicKey import RSA
from Crypto.Signature import PKCS1_PSS
from hashlib import md5
from hashlib import sha256
from Crypto.Hash import SHA256
import binascii
import base64
import time


# In[101]:


#
# User Authentication Handling Class
#
class User:
def __init__(self, private=None, public=None):
'''
A Simple Class To Handle User Authentication Activities

'''

if public:
self.publickey = public
else:
self.publickey = ''

if private:
self.privatekey = RSA.importKey(private)
else:
(self.privatekey, self.address) = self.generate_key_pair()

def generate_key_pair(self):
'''
Generate New Pair Of Keys For New Users

'''
private = None
public = None

# Random Number Generated
random = RSA.Random.new().read
PUB_LEN = 1024


# RSA Object
RSAKey = RSA.generate(PUB_LEN, random)

# Private Key
private = RSAKey.exportKey()

# Public Key
self.publickey = RSAKey.publickey().exportKey()

public = sha256(self.publickey).hexdigest()
public = sha256(public).hexdigest()
public = md5(public).hexdigest()

return (private, public)

def signature(self, data):
'''
Sign Data Using User Inserted/Generated Private Key
'''

r = RSA.importKey(self.privatekey)
siger = PKCS1_PSS.new(r)
h = SHA256.new(data)
sign = base64.b64encode(siger.sign(h))
return sign

#u = User()
#print u.publickey
#print u.privatekey
#print u.address
#print u.signature(u.address)


# In[102]:


# Global Functions

def previous_block_hash(blockitemdict):
'''
Global Function To Calculate previous block hashes
'''
return sha256("{index}{previoushash}{timestamp}{hash}{datahash}{nonce}{targetbit}".format(**blockitemdict)).hexdigest()



def transection_hash(data):
'''
Global Function To Calculate Transection hashes
'''
return sha256("{category}{txni}{coin}{fee}{signature}{time}".format(**data.getitems())).hexdigest()



def merkle_hash(dataload):
'''
A Simple Class That Automatically Calculate Hashes Of All Transection feilds using
Merkle Type Algorithm.

'''

# Two Empty Containers
hl1 = []
hl2 = []

for data in dataload:
hl1.append(transection_hash(data))

if not hl1:
return sha256('').hexdigest()

while True:
v1 = ''
v2 = ''
hl2 = []
if int(len(hl1) % 2)==0 and len(hl1)>1:
# Even Number's List

for h in hl1:

if not v1:
v1 = h
continue
v2 = h

hl2.append(sha256(v1+v2).hexdigest())
v1 = ''
v2 = ''

elif int(len(hl1) % 2)==1 and len(hl1)>1:
hl2 = hl1
hl2.append('')


elif len(hl1)==1:
return hl1[0]

else:
return False

hl1 = hl2

return False


# (
# category, --> mine, send, receive
# sender --> Sender Wallet Address
# receiver --> Receiver Wallet Address
# txni, --> input transection
# ccoin --> net balance
# coin, --> coin
# fee, --> transection fee
# time, --> time
# signature, --> hash = sha256(category + sender + receiver + txni + txno + coin + fee + time)
# hash = private_key_signature(hash)
#
#
# verification --> SENDER_PUBLIC_KEY
# )
def verify_transection(bco, transobj):
# Load Values From Transection Object
category = transobj.category
sender = transobj.sender
receiver = transobj.receiver
txni = transobj.txni
ccoin = transobj.ccoin
coin = transobj.coin
fee = transobj.fee
timestamp = transobj.time
signature = transobj.signature
verification = transobj.verification

# Check sender address length
if len(receiver)!=32:
print "[+] Condition No. 1 Failed By ", receiver
return False

# Check Current Transection Time With Previous block time
if not (float(timestamp) < float(time.time())):
print "[+] Condition No. 2 Failed By ", receiver
print "[-] Timestamp {}, Current Time {}".format(timestamp, time.time())
return False


# Miners Transection Conditions
if (category=='mine') and (sender!=''):
print "[+] Condition No. 3 Failed By ", receiver
return False

if (category=='mine') and txni:
print "[+] Condition No. 4 Failed By ", receiver
return False

if (category=='mine') and ccoin:
print "[+] Condition No. 5 Failed By ", receiver
return False

if (category=='mine') and (int(coin) != 25 ):
print "[+] Condition No. 6 Failed By ", receiver
return False

if (category=='mine') and fee:
print "[+] Condition No. 7 Failed By ", receiver
return False

if (category=='mine') and not signature:
print "[+] Condition No. 8 Failed By ", receiver
return False

if (category=='mine') and verification:
print "[+] Condition No. 9 Failed By ", receiver
return False

# Miners Conditions Close
if category=="mine":
return True

# Senders Conditions Verification
if (category=='send') and (len(sender)!=32):
print "[+] Condition No. 10 Failed By ", sender
return False

if (category=='send') and not txni:
print "[+] Condition No. 11 Failed By ", sender
return False

if (category=='send') and not coin:
print "[+] Condition No. 12 Failed By ", sender
return False

if (category=='send') and not fee:
print "[+] Condition No. 13 Failed By ", sender
return False

if (category=='send') and not signature:
print "[+] Condition No. 14 Failed By ", sender
return False

if (category=='send') and not verification:
print "[+] Condition No. 15 Failed By ", sender
return False


# Verify verification and sender address
public = sha256(verification).hexdigest()
public = sha256(public).hexdigest()
public = md5(public).hexdigest()



if not (public==sender):
print "[x] Invalid Sender Address : {} | {}".format(sender, public)
return False

# Verify Signature
h = category + sender + receiver + txni + coin + fee + timestamp
h = sha256(h).hexdigest()
h = SHA256.new(h)

r = RSA.importKey(verification)
sign_verify = PKCS1_PSS.new(r)
dsignature = base64.b64decode(signature)

if not sign_verify.verify(h, dsignature):
print "[x] Signature Invalid. Transection Index {} | Sender {} ".format(txni, sender)
return False

print "[+] Transection Signature Verified."

#
# So, Previous Conditions Verified That Request Is Generated From Real User
#
# Now, Let's Do Some mathematical Calculations for Amount.
#

input_transections = []
balance = 0.0

n = len(txni)/64
for i in range(n):
input_transections.append(txni[i*64: (i+1)*64])


for pretxnid in input_transections:
if bco.double_spend_check(sender, pretxnid):
print "[x] Double Spend Detected. Transection Index {}, InputTransection {}".format(txni, pretxnid)
return False
# Find Transections Into Blockchain
data = bco.search_transection_dict(pretxnid)

if not data:
print "[x] Invalid Transection Input."
return False
#{
# 'category'
# 'sender'
# 'receiver'
# 'fee': '',
# 'ccoin': '',
# 'txni': '',
# 'time': '1526936989.86',
# 'signature': '40eee107b43f2254ef8ea5c9d15f63bba6e872bb2421b3da09173fb88cdd1c8c6578bfe7780cc1d5223c289c95dbbb9bfcc303cd9379e4f47ea7ca095b1e1e4125ed6fbb3c072901dc7c45e34faeeccec1b07bbe972ed94f354a1153ed9ecca402098e64eaf07621d8b35deaa8bcd003edc8f3d8770a93627f8e073d4b1c6ff6',
# 'coin': '25'
#}
# Verify Input Transection Signatures
load = data['load']

if load['receiver']==sender:
#
# Taking Balance Inputs From Receiving Transections
#

# Verify Signature
tmp = load['category'] + load['sender'] + load['receiver'] + load['txni'] + load['coin'] + load['fee'] + load['time']
tmp = sha256(tmp).hexdigest()
tmp = SHA256.new(tmp)
dsignature = base64.b64decode(load['signature'])

if sign_verify.verify(tmp, dsignature):
print "[+] Input Transection {} \n\t\tVerified By {}".format(pretxnid, sender)
else:
print "[-] Input Transection {} \n\t\tVerification Failed By {}".format(pretxnid, sender)
return False

balance+= float(load['coin'])

elif load['sender']==sender:
#
# Taking Inputs From Transection Balance Changes
#
balance+= float(load['ccoin'])

else:
print "[-] Something Wrong With Conditions."
print load
pass


if balance==0.0:
print "[x] Insuffecient Balance"
return False


if balance < float(float(coin)+float(fee)+float(ccoin)):
print "[x] Low Balance"
return False

return balance



# In[103]:


#
# trasenction feild structure
# (
# category, --> mine, send, receive
# sender --> Sender Wallet Address
# receiver --> Receiver Wallet Address
# txni, --> input transection
# txno, --> output transection
# ccoin --> net balance
# coin, --> coin
# fee, --> transection fee
# time, --> time
# signature, --> hash = sha256(category + sender + receiver + txni + txno + coin + fee + time)
# hash = private_key_signature(hash)
#
#
# verification --> SENDER_PUBLIC_KEY
# )
#
# Trasenction Unique Identities
#
# structure
# (
#
# Name : SHA256( sender + receiver ) ---> Result Hash Will Be Same
# if Sender and Reciever are same (Not Unique)
# txnid : SHA256( Name + Signature) --> Always Unique
#
# txn : trasenction feild
#
# )
#
#
#
#







# Simple Request Transection ()
class RequestTransection:
def __init__(self, user):
'''
A Simple Class To Handle And Generate Valid Transection Requests
Using User Object Authentication Object.

'''
self.category = ''
self.user = user
self.sender = None
self.receiver = None
self.txni = []
self.ccoin = ''
self.coin = ''
self.time = ''
self.fee = ''
self.signature = ''
self.transection = {}
self.verification = ''

def getitems(self):
'''
Get All Feild Items
'''
time.sleep(1)
return {
"category" : self.category,
'sender': self.sender,
'receiver' :self.receiver,
"txni" : self.txni,
"ccoin" : self.ccoin,
"coin" : self.coin,
"fee" : self.fee,
"signature" : self.signature,
"time" : self.time,

}

def __repr__(self):
return "< transReq {} | {} >".format(self.category, self.time)


def create_transection(self, category='mine', txni=[], coin='',
fee='', receiver = '', sender = '', ccoin=''):
'''
Generate Valid Transection Request With Automatic Hash And Signature handling
'''
if not sender:
sender = self.user.address

if category=="mine":
sender =''
receiver = self.user.address

if not receiver:
raise "please insert valid receiver address."

# Lower case --- > category
category = category.lower()

# Check category
if category not in ['mine', 'send']:
raise "please use valid categories like mine or send "


# initialise values
self.category = category
self.sender = sender
self.receiver = receiver
self.txni = ''.join(i for i in txni)
self.coin = coin
self.ccoin = ccoin
self.fee = fee
self.time = str(time.time())
#
# signature, --> hash = sha256(category + sender + receiver + txni + coin + fee + time)
# private_key_signature(hash)
#
h = self.category + self.sender + self.receiver + self.txni + self.coin + self.fee + self.time
h = sha256(h).hexdigest()


if self.category!="mine":
self.verification = self.user.publickey

self.signature = self.user.signature(h)

self.transection = {
"name" : sha256(self.sender + self.receiver).hexdigest(),
"txn" : sha256( sha256(self.sender + self.receiver).hexdigest() + self.signature).hexdigest(),
"load" : self.getitems(),

}
return


# In[104]:


#
#
# RequestBlock Object handler
#
# Structure
# (
# index ---> current block index in chain
# previoushash ---> previous block hash
# timestamp ---> timestamp
# targetbit ---> difficulty bit in hash calculation
# hash ---> self block hash (proof of work)
# datahash ---> datahash (merkle hash of transection feilds)
# dataload ---> all transection data
# nonce ---> nonce (proof of work)
# )
#
#
#
#
#
class RequestBlock:
def __init__(self, bco, targetbit=4, transbuffer = []):
'''
A Simple Class To Handle All Transection Request And Generate A Valid Block.
'''
self.bco = bco # SimpleBlockChain Class Object
self.index = self.bco.check_chain_len()+1

if self.bco.pre_block():
self.previoushash = previous_block_hash(self.bco.pre_block())
else:
self.previoushash = ''

self.timestamp = str(time.time())
self.targetbit = targetbit
self.hash = ''
self.datahash = ''
self.dataload = []
self.nonce = ''
self.transbuffer = transbuffer
self.calculate_block()



def calculate_block(self):
'''
Calculate Block Hash
'''
# load transections from Node Buffer
self.load_data_from_network_buffer()
tmp = merkle_hash(self.dataload)
if not tmp:
print "[Note] No Data load Found"
self.datahash = tmp
return


def load_data_from_network_buffer(self):
'''
Load Trasection Requests
'''
senders = []
for trans_req in self.transbuffer:
if trans_req not in self.dataload:
if verify_transection(self.bco, trans_req):
if trans_req.sender not in senders:
self.dataload.append(trans_req)
senders.append(trans_req.sender)
else:
print "[x] Double Transection Request Found. ", trans_req
else:
print "[x] Transection Verification Fail.", trans_req
return

def getitems(self):
'''
return items
'''
return {
"index" : self.index,
"previoushash": self.previoushash,
"timestamp" : self.timestamp,
"targetbit" : self.targetbit,
"hash" : self.hash,
"datahash" : self.datahash,
"dataload" : [i.transection for i in self.dataload],
"nonce" : self.nonce,
}


# In[105]:


#
# Class Design To Perform Proof Of Work Hash Calculations
#
class MineBlock:
'''
A Simple Class That will Automatically handle Block Mining And Other Important Stuff.

'''
def __init__(self, block_chain_obj):
self.bco = block_chain_obj
self.pow = False
self.block = ''
self.difficulty = 0

def block_validator(self, block):
# Check Index
# Check PRevious hash
# check timestamp
# check merkle hash


if self.bco.check_chain_len()==0:
previoushash = True

else:
previoushash = block.previoushash == previous_block_hash(self.bco.pre_block())#sha256("{index}{previoushash}{timestamp}{hash}{datahash}{nonce}{targetbit}".format(**self.pre_block())).hexdigest()

timestamp = float(block.timestamp) < time.time()

index = block.index == self.bco.check_chain_len()+1

datahash = merkle_hash(block.dataload)

if previoushash and timestamp and index and datahash:
return True

print "[+] Block Condition Failur During MineBLock Verification."
print "[-] Previous hash verify : ", previoushash
#print "[-] Proof Of Work verify : ", proof_of_work_hash
print "[-] Timestamp verify : ", timestamp
print "[-] Block Index verify : ", index
print "[-] Block Datahash verify : ", datahash
return False

def load(self, block):
'''
Load Block
'''

time.sleep(2) # To pass timestamp condition


if self.block_validator(block):
self.block = block
self.difficulty = int(self.block.targetbit)
self.proof_of_work_number_generator()
self.pow = True
return True

return False

def getblock(self):
return self.block

def getitems(self):
return self.block.getitems()

def proof_of_work_number_generator(self):
self.block.nonce = 0
while sha256("{}{}{}{}{}".format(self.block.previoushash,self.block.datahash,self.block.timestamp,self.block.targetbit,self.block.nonce)).hexdigest()[:self.difficulty]!='0'*self.difficulty:
self.block.nonce+= 1
self.block.hash = sha256("{}{}{}{}{}".format(self.block.previoushash,self.block.datahash,self.block.timestamp,self.block.targetbit,self.block.nonce)).hexdigest()
return self.block.nonce



# In[106]:


#
# Class To handle Block chain database and act as a central sever to handle all block request
#
class SimpleBlockChain:
'''
A Simple Class To Handle Block Chain Database.
'''
def __init__(self, dbname='ChainStore.json', targetbit = 4):
self.targetbit = targetbit
self.dbname = dbname

# Check BlockChain Json Storage File
if os.path.exists(self.dbname):
self.chain = json.load(open(self.dbname, 'r'))
else:
self.chain = {
"blockchain": [],
'lastupdate': time.time(),
}


# Check BlockChain Status
if not self.check_chain_len():

# Add Genesis Block
self.add_genesis_block()

def getchain(self):
return self.chain

def search_transection_dict(self, txnid):
for b in self.chain['blockchain'][::-1]:
for l in b['dataload']:
if l['txn']==txnid:
return l
return False

def get_all_transections(self, address):
rectxn = []
sentxn = []
for b in self.chain['blockchain'][::-1]:
for l in b['dataload']:
txn = l['txn']
n = l['load']
if n['sender']==address:
sentxn.append(l)
if n['receiver']==address:
rectxn.append(l)

return (rectxn, sentxn)


# add genesis block request
def add_genesis_block(self):
'''
Add Genesis Block
'''
print "[+] Add Genesis Block Request."
tmpobj = RequestBlock(self)
mineblock = MineBlock(self)
mineblock.load(tmpobj)
self.new_block_request(mineblock.getblock())
return

# New Blocking Join Request
def new_block_request(self, block):
'''
New Block Request
'''
# Verify Block
if self.validate_new_block(block):
self.chain['blockchain'].append(block.getitems())

print "[+] Request Block Verified. Index : ", block.index
else:
print "[Error] Request Block Is Not Valid."
return


# Validate New Block Before Joining It to main Chain
def validate_new_block(self, block):
'''
Validate And Verify Various Hash Calculations
'''
# check target bit
# check block index
# check previous block hash
# check timestamp
# check datahash

diff = self.targetbit == int(block.targetbit)

if self.check_chain_len()==0:
previoushash = True

else:
previoushash = block.previoushash == previous_block_hash(self.pre_block())#sha256("{index}{previoushash}{timestamp}{hash}{datahash}{nonce}{targetbit}".format(**self.pre_block())).hexdigest()

proof_of_work_hash = sha256("{previoushash}{datahash}{timestamp}{targetbit}{nonce}".format(**block.getitems())).hexdigest()[:block.targetbit]=='0'*block.targetbit

timestamp = float(block.timestamp) < time.time()

index = block.index == self.check_chain_len()+1

datahash = merkle_hash(block.dataload)

if previoushash and proof_of_work_hash and timestamp and index and datahash and diff:
return True



print "[+] Block Condition Failur During SimpleBLockChain Verification Member Function."
print "[-] Previous hash verify : ", previoushash
print "[-] Proof Of Work verify : ", proof_of_work_hash
print "[-] Timestamp verify : ", timestamp
print "[-] Block Index verify : ", index
print "[-] Block Datahash verify : ", datahash
print "[-] Block Targetbit verify: ", diff
return False

# Check block chain length
def check_chain_len(self):
return len(self.chain['blockchain'])

def pre_block(self):
if self.chain['blockchain']:
return self.chain['blockchain'][-1]
#return

# save updates
def close(self):
f = open(self.dbname, 'w')
self.chain['lastupdate']= time.time()
json.dump(self.chain, f, sort_keys=True, indent=4, separators=(',', ': '))
f.close()
return


def get_address_trans(self, address):
received = []
sent = []
changes = []

retxn, setxn = self.get_all_transections(address)

# Receiving Transection List
for r in retxn:
received.append((float(r['load']['coin']), r['txn']))

# Spent Transection list
for s in setxn:
sent.append((float(s['load']['coin'])+float(s['load']['fee']), s['txn']))

if s['load']['ccoin']:
changes.append((float(s['load']['ccoin']), s['txn']))

return (received, sent, changes)

def get_address_balance(self, address):
rec, sen, cha = self.get_address_trans(address)

r = 0.0
s = 0.0
for amount, txnid in rec:
r+= amount
for amount, txnid in sen:
s+= amount

return r-s

def double_spend_check(self, address, txn):
rcv, snt = self.get_all_transections(address)
input_transections = []

for t in snt:
k=t['load']['txni']
n = len(k)/64
for i in range(n):
tmp = k[i*64: (i+1)*64]
if tmp:
input_transections.append(tmp)

if txn in input_transections:
print "[X] Double Spend Found : ", txn

return True
print "[x] Double Spend Clear : ", input_transections, txn
return False









# In[107]:


class PleaseMine:
def __init__(self, sbc, auth, transreq = []):
self.sbc = sbc
self.auth = auth
self.drop_fraud_minning_requests(transreq)
self.add_award_transection()

def drop_fraud_minning_requests(self, transreq):
self.transreq = []

for trans in transreq:
if trans.category=="mine":
pass
elif trans.category=='send':
self.transreq.append(trans)
else:
print "[x] Unknown Input Transections : ", transreq
return

def add_award_transection(self):
req = RequestTransection(self.auth)
#create_transection
req.create_transection(category='mine',
coin='25',
receiver = self.auth.address)
self.reward_txn = req.transection
self.transreq.append(req)

# assemble all transection and create a block object
reqblock = RequestBlock(
self.sbc,
transbuffer=self.transreq
)

# Miner Object
mineblock = MineBlock(self.sbc)


# Load Block and find proof of work
mineblock.load(reqblock)


# print proof of work
#print mineblock.getitems()

# insert block object to blockchain handler
self.sbc.new_block_request(mineblock.getblock())

return




# In[108]:


import os
import pickle


# In[109]:



class Wallet:
def __init__(self, db = 'walletdb.json'):
self.dbname = db
self.username = None
self.password = None

self.retreive_wallet()


def create_new_user(self, username, password):
# Create User Authentication Object
u = User()

self.db[username+password] = {
'auth': pickle.dumps(u),
'rtxn': [],
'stxn': [],
'bal' : [],
}

return

def check_account(self, username, password):
if username+password in self.db.keys():
return True
return False

def load_account(self, username, password):
if self.check_account(username, password):
self.auth = pickle.loads(self.db[username+password]['auth'])
self.rtxn = self.db[username+password]['rtxn']
self.stxn = self.db[username+password]['stxn']
self.bal = self.db[username+password]['bal']
return

def retreive_wallet(self):
if os.path.exists(self.dbname):
self.db = json.load(open(self.dbname, 'r'))
else:
self.db = {}

return

def refresh(self):
self.close()
self.retreive_wallet()
return

def close(self):
tmp = open(self.dbname, 'w')
json.dump(self.db, tmp, sort_keys=True, indent=4, separators=(',', ': '))
tmp.close()
return



# In[110]:



if __name__=='__main__':
# -----------------------------------------------------------
# ================= Global Object ===========================
# -----------------------------------------------------------
# Create Blockchain handler object
sbc = SimpleBlockChain()


w = Wallet()
w.create_new_user('suraj', 'singh')
w.refresh()
w.load_account('suraj', 'singh')
# ------------------------------------------------------------
# ==================== Miner =================================
# ------------------------------------------------------------


# Create User Authentication Object
u = w.auth #= User()
print "[*] Miner Address : ", u.address


# [Mining First Block]
miner = PleaseMine(sbc, u)
print "[*] Miner Reward : ", miner.reward_txn['txn']


# ------------------------------------------------------------
# ==================== Nodes =================================
# ------------------------------------------------------------

node = User() # Example Node
print "[*] Node Address : ", node.address
# Create Transection Request object
n_address = node.address # Shared its receiving address with miners.. because at this time,
# miner is the only one account that contain 25 coins


# Miner Requested A Transection
req = RequestTransection(u)
req.create_transection(category='send',
sender=u.address,
receiver=n_address,
fee='0.1' ,
coin='20',
ccoin = str(25.0-(20.0+0.1)),
txni= miner.reward_txn['txn']
)
req1 = RequestTransection(u)

req1.create_transection(category='send',
sender=u.address,
receiver=n_address,
fee='0.1' ,
coin='20',
ccoin = str(25.0-(20.0+0.1)),
txni= miner.reward_txn['txn'][::-1]
)
transer_money_reference_ = req.transection

print "[+] Changes Left : ", req.ccoin

# Wait... To Add This Block... Miner Again Need To Use its Computational Power... So,,


u1 = User()
#PleaseMine(sbc, u1, transreq=[req])
#PleaseMine(sbc, u1, transreq=[req1])
#PleaseMine(sbc, u1, transreq=[req, req1])


sbc.close()


# In[111]:



print sbc.get_address_balance(u.address)

#retxn, setxn = sbc.get_all_transections(node.address)








To Run This Script.
Just Type:


$ python path/to/script.py

Blockchain JSON Output





{
"blockchain": [
{
"datahash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
"dataload": [],
"hash": "00006284e622e53b43465efa8364dc1276a9b95f2527cc3884b272471ca646d3",
"index": 1,
"nonce": 40892,
"previoushash": "",
"targetbit": 4,
"timestamp": "1527104940.71"
},
{
"datahash": "0bab71baf46e56008a760bd1893585be7cc11d128128b120fb3584691d949fd5",
"dataload": [
{
"load": {
"category": "mine",
"ccoin": "",
"coin": "25",
"fee": "",
"receiver": "d8c649dba3d74c641404658208dac1fb",
"sender": "",
"signature": "eMlXEm91bUf7hsDGCLjmHgD6Xr3LhhY9TSAjWSuqDNYQBhQ1hFCrmi9FIzDruoR2uatDrhmYz2fD8Ia6PxVZJ7mPC9RPaeNE2NGhqoF/wyyZX/nnqQRDZfYF75BY0PtUI8HqBm2vn6mKANAeiUfZ9uEdc48aMBdmHl70MD4p4JA=",
"time": "1527104942.9",
"txni": ""
},
"name": "b365d2a9061472e2ed270755ce96e88e280509d45d9a0ce1f1dfe4b89250f094",
"txn": "2e325a95a6a1d00e8ac4af041061ad5bfd6c767196c90df111b6d685b38d6037"
}
],
"hash": "0000a15c752c3352cac66858db17a2525cd12105978da2cfdeaa90b228b9c670",
"index": 2,
"nonce": 96223,
"previoushash": "bdeec364fa8bf87075a5d2e0067b58e396693417f12a04cd397978d635a2660a",
"targetbit": 4,
"timestamp": "1527104943.9"
}
],
"lastupdate": 1527104951.334412
}