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A hands-on tutorial about building digital cash (Bitcoin)

Home Page: https://buidlbootcamp.com/

Jupyter Notebook 7.35% Python 92.48% Dockerfile 0.17%

digital-cash's Introduction

BUIDL Bootcamp

If you're on Windows, watch this video. Otherwise:

Step 1: Git

Git is the primary collaboration software for software development -- like Google Docs for programmers.

To check whether you have it installed go to your terminal, type “git” and hit enter. If you don’t see a bunch of instructions (see pic below), you don’t have git installed and need to install Git

Step 2: Github

Create a GitHub account if you don’t already have one.

Step 3: Python

Go to your terminal, type “python3” and hit enter. If you don’t see a “python prompt” (see pic below) then you need to install Python 3. Hit control-d or call the python exit() function to exit.

Step 4: Clone the Project with Git, install dependencies, and run it

git clone https://github.com/justinmoon/digital-cash.git
cd digital-cash
python3 -m venv venv
source venv/bin/activate
python3 -m pip install -r requirements.txt
jupyter notebook

This will open up your web browser to a page that looks like the image below. This is Jupyter Notebook, which is basically a little website that’s run on only your computer.

Click the "PNGCoin Workbook.ipynb" link to follow along with this first lesson.

Using Jupyter Notebook

Check out this tutorial to learn more about using Jupyter Notebook.

If you stop Jupyter for any reason and later want to restart it:

cd digital-cash
source venv/bin/activate
jupyter notebook

digital-cash's People

Contributors

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digital-cash's Issues

Don't us "!ls | grep" in PNGCoin

use python standard library

Windows setup instruction in README

socket.connect(("0.0.0.0", port)) fails on Windows

2 separate reports of [WinError 10049] The requested address is not valid in its context when this is attempted.

Replacing "0.0.0.0" with "localhost" resolved the error.

I should be able to just replace this across the board because "localhost" would work just fine on Unix so long as this isn't running within docker.

PowerShell execution policy

I tested the windows instructions using PowerShell. The only hiccup was that I needed to run Set-ExecutionPolicy -ExecutionPolicy Unrestricted or the activate command would fail. One could assume that a powershell user knows how to work around this problem, but it probably wouldn't hurt to include it in the readme.

Update README

ECDSACoin: TypeError when calling get_owner function

I get the following error when I run get_owner(coin):

TypeError: unhashable type: 'VerifyingKey'

Here's a timestamp of the ECDSACoin video where the code is executed:
https://www.youtube.com/watch?v=hujedHkaxLI&feature=youtu.be&t=2578

Traceback shows it is coming from this statement:

database = {
    bob_public_key: "Bob",
    alice_public_key: "Alice",
    bank_public_key: "Bank"
}

In the Traceback it has an arrow pointing to the bank_public_key: "Bank" line, but if I comment out that line then I get the same error but the arrow points to the alice_public_key: "Alice" line. And if I comment out that one it points to bob's line.

If I try to print(public_key) It prints:

ecdsa.keys.VerifyingKey object at 0x.........>

I'm running Python 3.6.3 and encounter this error with the ECDSACoin workbook noteobook as well as the solution notebook.

I was able to finish the ECDSACoin as it doesn't actually require get_owner.

Unable to pip install -r requirements.txt with python 3.9.7 on MacOS 10.15.7

When I try to install the dependencies with pip install -r requirements.txt I get installation errors.

I've resolved a few of the dependency errors up by upgrading packages up until jupyter. There's an installation error that I can't resolve in one of the dependencies of this package.

I've also tried using pyenv to run python 3.7.X for this project but pyenv doesn't play nicely with python 3.9

Env details:
MacOS 10.15.7
python 3.9.7

BankCoin's transaction handler fails silently, code here differs from video

2 problems.

The code in the video has a try/except block which silently eats errors. Happens around 1:52:00 of video
This isn't how the code works in the "canonical video"

ECDSACoin: get_owner doesn't work after retrieving coin from disk

Steps to recreate bug:

Create a coin with Alice's public key
Save to disk
Retrieve coin from disk
Run get_owner with that coin

This bug is fixed by serializing the keys in get_owner. See below:

def get_owner(coin):
    database = {
        serialize(bob_public_key): "Bob",
        serialize(alice_public_key): "Alice",
        serialize(bank_public_key): "Bank"
    }
    public_key = serialize(coin.transfers[-1].public_key)

    return database[public_key]