started the fix

app.py

@@ -1,12 +1,11 @@
 #!/usr/bin/env python
-"""Flask server to serve the block API."""
 
-import json
 from time import time
-import argparse
-from uuid import uuid4
 from flask import Flask, request
+import json
+from uuid import uuid4
 from blockchain import Blockchain, Transaction, Block
+import argparse
 
 parser = argparse.ArgumentParser(description="A blockchain simulation")
 parser.add_argument("-p", "--port", type=int, help="Port number", default=80)
@@ -16,19 +15,18 @@ port = args.port
 
 app = Flask(__name__)
 
-NODE_IDENTIFIER = str(uuid4()).replace("-", "")
+node_identifier = str(uuid4()).replace("-", "")
 
 blockchain = Blockchain()
 
 
 @app.route("/mine", methods=["GET"])
 def mine():
-    """Mine samy coin."""
     last_block = blockchain.blocks[-1]
     last_proof = last_block.proof
     proof = blockchain.proof_of_work(last_proof)
 
-    transaction = Transaction("Network", NODE_IDENTIFIER, 50)
+    transaction = Transaction("Network", node_identifier, 50)
     blockchain.new_transaction(transaction)
     block = Block(
         len(blockchain.blocks) + 1,
@@ -44,7 +42,6 @@ def mine():
 
 @app.route("/transactions/new", methods=["POST"])
 def new_transaction():
-    """Submit a new transaction."""
     values = request.get_json()
     transaction = Transaction(values["sender"], values["recipient"], values["amount"])
     blockchain.new_transaction(transaction)
@@ -54,29 +51,27 @@ def new_transaction():
 
 @app.route("/chain", methods=["GET"])
 def chain():
-    """Display the block chain."""
     return json.dumps([b.__dict__ for b in blockchain.blocks])
 
 
 @app.route("/nodes", methods=["GET"])
 def nodes():
-    """List known nodes."""
     return json.dumps(list(blockchain.nodes))
 
 
 @app.route("/register", methods=["POST"])
 def register_nodes():
-    """Register a new node."""
-    json_values = request.get_json()
-    for node in json_values["nodes"]:
+    values = request.get_json()
+    nodes = values["nodes"]
+
+    for node in nodes:
         blockchain.register_node(node)
 
     return "New node has been added\n"
 
 
 @app.route("/resolve", methods=["GET"])
-def resolve():
-    """Resolve the blockchain."""
+def consensus():
     replaced = blockchain.resolve_conflicts()
 
     if replaced:

blockchain.py

@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+"""Block chain according to me."""
 
 import hashlib
 from time import time
@@ -10,6 +11,7 @@ DIFFICULTY = 4
 
 
 class Block:
+    """Block according to me."""
     def __init__(self, index, timestamp, transactions, previous_hash, proof):
         self.index = index
         self.timestamp = timestamp
@@ -19,6 +21,7 @@ class Block:
         self.hash = self.hash()
 
     def hash(self):
+        """Hash a block using sha256."""
         data = self.__dict__
         data["transactions"] = [t.__dict__ for t in self.transactions]
         block_string = json.dumps(data, sort_keys=True).encode()
@@ -29,16 +32,19 @@ class Block:
 
 
 class Transaction:
+    """Transaction of Samy coin."""
     def __init__(self, sender, recipient, amount):
         self.sender = sender
         self.recipient = recipient
         self.amount = amount
 
     def __str__(self):
+        """String representation of a transaction."""
         return f"FROM: {self.sender} TO: {self.recipient} AMOUNT: {self.amount}"
 
 
 class Blockchain:
+    """Blockchain"""
     def __init__(self):
         self.blocks = []
         self.blocks.append(self.create_first_block())