A class group project, realize a blockchian system with python 3.0 and pickledb. Functions are added like mine blocks, add transactions, consensus and get blocks.

This blockchain system can be divided into three layers.

Nodes can perform different operations by sending HTTP requests with data in JSON format. Nodes can also see response message in the Postman. For example, nodes can mine a new block via “/mine” and get a response about the information of the new block.

Set different routes to receive HTTP requests and invoke corresponding back-end Python functions. After that, reply the node with data in JSON format. The back-end Python functions will be invoked to deal with the service logic and execute database operations.

pickleDB can store the blockchain data in the disk.

Programming language: Python 3.6. Python packages:Flask 1.0.2 and requests 2.20.1. Database: pickleDB 0.8.1. Operation system: Windows 10 64bit build 1803 and macOS High Sierra 10.13.6. Integrated Development Environment: PyCharm Professional Edition 2018.2. Other tool(s): Postman 6.5.3.

All the operations are implemented via sending HTTP requests. Nine routes have been defined for different operations:
(1) /restart Reset your own blockchain.
(2) /nodes/register Registration for new nodes.
(3) /transactions/new Create a new transaction.
(4) /mine Mine a new block.
(5) /chain View your own blockchain information.
(6) /pool View the current transactions pool information.
(7) /nodes/resolve Solve conflicts with other nodes.
(8) /getblocks Get other nodes’ blockchain information.
(9) /inv Tell the requester about its own blockchain information.

XIA Yuchen
Network – realize the interactions among different nodes.
HUANG Kaihang
Project solution and project framework – choose the appropriate technology and tools for the project. Flask web application framework – use Flask to set up routes for different HTTP requests to invoke back-end functions. Data persistence – store the data in the disk.
ZENG Lin
Blockchain prototype – construct the blockchain system according to the requirements. HU Weihua
Mining – implement a fixed-difficulty Proof-of-Work algorithm