From 359ebf613e12dd51b63751a4948f135f81263ce6 Mon Sep 17 00:00:00 2001
From: Daxeel Soni <daxeel_soni4444@yahoo.com>
Date: Fri, 2 Feb 2018 12:06:48 +0530
Subject: [PATCH] chain.py documented

---
 blockchain/chain.py | 43 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 41 insertions(+), 2 deletions(-)

diff --git a/blockchain/chain.py b/blockchain/chain.py
index 1c48c2f..894696e 100644
--- a/blockchain/chain.py
+++ b/blockchain/chain.py
@@ -1,3 +1,17 @@
+# -*- coding: utf-8 -*-
+# ===================================================
+# ==================== META DATA ===================
+# ==================================================
+__author__ = "Daxeel Soni"
+__url__ = "https://daxeel.github.io"
+__email__ = "daxeelsoni44@gmail.com"
+__license__ = "MIT"
+__version__ = "0.1"
+__maintainer__ = "Daxeel Soni"
+
+# ==================================================
+# ================= IMPORT MODULES =================
+# ==================================================
 import hashlib
 import datetime
 import json
@@ -5,9 +19,13 @@ from colorama import Fore, Back, Style
 import time
 import sys
 
-# index, timestamp, previousHash, blockHash, data
-
+# ==================================================
+# =================== BLOCK CLASS ==================
+# ==================================================
 class Block:
+    """
+        Create a new block in chain with metadata
+    """
     def __init__(self, data, index=0):
         self.index = index
         self.previousHash = ""
@@ -17,10 +35,16 @@ class Block:
         self.hash = self.calculateHash()
 
     def calculateHash(self):
+        """
+            Method to calculate hash from metadata
+        """
         hashData = str(self.index) + str(self.data) + self.timestamp + self.previousHash + str(self.nonce)
         return hashlib.sha256(hashData).hexdigest()
 
     def mineBlock(self, difficulty):
+        """
+            Method for Proof of Work
+        """
         print Back.RED + "\n[Status] Mining block (" + str(self.index) + ") with PoW ..."
         startTime = time.time()
 
@@ -33,15 +57,27 @@ class Block:
         print Back.BLUE + "[ Info ] Mined Hash : " + self.hash
         print Style.RESET_ALL
 
+# ==================================================
+# ================ BLOCKCHAIN CLASS ================
+# ==================================================
 class Blockchain:
+    """
+        Initialize blockchain
+    """
     def __init__(self):
         self.chain = [self.createGenesisBlock()]
         self.difficulty = 3
 
     def createGenesisBlock(self):
+        """
+            Method create genesis block
+        """
         return Block("Genesis Block")
 
     def addBlock(self, newBlock):
+        """
+            Method to add new block from Block class
+        """
         newBlock.index = len(self.chain)
         newBlock.previousHash = self.chain[-1].hash
         newBlock.mineBlock(self.difficulty)
@@ -49,6 +85,9 @@ class Blockchain:
         self.writeBlocks()
 
     def writeBlocks(self):
+        """
+            Method to write new mined block to blockchain
+        """
         dataFile = file("chain.txt", "w")
         chainData = []
         for eachBlock in self.chain: