Py3_BlockchainInfoAPI.py

# -*- coding: utf-8 -*-
"""
Created on Sat Apr 21 12:37:05 2018

@author: Gareth

Validate an imported block against Blockchain.info's api
https://blockchain.info/api

Respects API's request limting queries to 1 every 10s

Queries for blocks are done using block hash, and are returned in json format
"""

# %% Imports

import requests
import time
from pybit.py3.chain import Dat


# %% Get genesis block from Blockchain.info api

# api url
url = "https://blockchain.info/rawblock/"
# Query by blockhash
blockHash = "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"
# Query
resp = requests.get(url + blockHash)

# Check reponse 200
if resp.status_code == 200:
    print("Good response")
else:
    print("Bad response code {}".format(resp.status_code))


# %% Look at response

# Print block info
print(resp.json())

# Print individual fields, eg
print("\n")
print(resp.json()['bits'])
print(resp.json()['mrkl_root'])


# %% Function version

def get_resp(h,
             lastTime=0,
             url="https://blockchain.info/rawblock/",
             pr=True):

    # Wait if last query was less than 10s ago
    dTime = (time.time() - lastTime)
    if dTime < 11:
        sleep_time = 11 - dTime
        if pr:
            print("Sleeping for {0}".format(sleep_time))
        time.sleep(sleep_time)

    # Query
    print(url+h)
    resp = requests.get(url + h)

    # Record the last time
    lastTime = time.time()

    if resp.status_code == 200:
        # Get the json
        jr = resp.json()
    else:
        # Or return the response code on error
        print(resp.status_code)
        jr = None

    return jr


def block_validate(block,
                   pr=True,
                   **kwargs):
    """
    Query a block hash from Blockchain.info's api. Check it matches the block
    on size, merkle root, number of transactions, previous block hash

    Respects apis request limting queries to 1 every 10s.
    """
    # Wait if last query was less than 10s ago
    jr = get_resp(block.hash,
                  url="https://blockchain.info/rawblock/",
                  **kwargs)

    if jr is not None:
        # Check size
        t1 = jr['size'] == block.blockSize
        if pr:
            print(t1)

        # Check merkle root
        t2 = jr['mrkl_root'] == block.merkleRootHash
        if pr:
            print(t2)

        # Check number of transactions
        t3 = jr['n_tx'] == block.nTransactions
        if pr:
            print(t3)

        # Check previous block hash
        t4 = jr['prev_block'] == block.prevHash
        if pr:
            print(t4)

    else:
        t1 = t2 = t3 = t4 = False
   
    # The the overall result
    result = t1 & t2 & t3 & t4

    # Report
    if pr:
        if result:
            print("Pass")
        else:
            print("Fail")

    return lastTime, result


# Load a block
f = 'Blocks/blk00000.dat'
dat = Dat(f,
          verb=5)

dat.read_next_block()
block = dat.blocks[0]

# Reset timer
lastTime = 0
# Query using this block hash
lastTime, result = block_validate(block)

# Run same query again to test wait timer
print("\n")
lastTime, result = block_validate(block, lastTime)


# %% Transaction validation

# Get a transaction hash
transHash = dat.blocks[0].trans[0].hash

print(transHash)

# api url
url = "https://blockchain.info/rawtx/"
# Query
resp = requests.get(url + transHash)

# Check reponse 200
if resp.status_code == 200:
    print("Good response")
else:
    print("Bad response code {}".format(resp.status_code))


# %% Look at response

# Print block info
print(resp.json())

# Print individual fields, eg
print("\n")
# Script from input 0
print(resp.json()['inputs'][0]['script'])
# Transaction hash
print(resp.json()['hash'])
# Some meta info for output 0 (not in block)
print(resp.json()['out'][0]['addr_tag'])
# Decoded output address
print(resp.json()['out'][0]['addr'])


# %% Function version

def trans_validate(trans,
                   pr=True):
    """
    Query a transaction hash from Blockchain.info's api.
    Check it matches on:
        - Stuff

    Respects apis request limting queries to 1 every 10s.

    Handles single input
    """

    jr = get_resp(trans.hash,
                  lastTime=0,
                  url="https://blockchain.info/rawtx/",
                  pr=True)

    # Input 0 script
    t1 = jr['inputs'][0]['script'] == trans.txIn[0].scriptSig
    if pr:
        print(t1)

    # Output 0 script
    t2 = jr['out'][0]['script'] == trans.txOut[0].pkScript
    if pr:
        print(t2)

    # Decoded output address
    t3 = jr['out'][0]['addr'] == trans.txOut[0].outputAddr
    if pr:
        print(t3)

    # The the overall result
    result = t1 & t2 & t3

    # Report
    if pr:
        if result:
            print("Pass")
        else:
            print("Fail")

    return lastTime, result


trans = dat.blocks[0].trans[0]
trans_validate(trans)