Marnee Dearman (KG7SIO)

Hashcash in F#

Implementing the hashcash algorithm in F#

Why am I doing this?

The hashcash algorithm forms this basis of cryptocurrencies like Bitcoin. I have been getting into this kind of technology, like the blockchain and cryptocurrency, lately (this is the future!) and I thought it would be fun to try to implement the hashcash algorithm in F#. Plus the proof-of-work system seems to . . .

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August 05, 2017

Low-fuss database migrations

Migrate your database from source control at build time with TeamCity and SQL Compare

Why am I doing this?

At work, I have been working on getting our applications into the build pipeline (in TeamCity). I have been making good progress on the application side but a lot of our database migrations were still kind of manual. I would inevitably end up with a failing build because I forgot to open up SQLCompare, compare . . .

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July 24, 2017

Deploy your Python code to AWS Lambda using the CLI

How to get started creating and deploying a Python package

Why am I doing this?

The AWS provided tutorials are too much stuff. Here I have simplified it. Plus I needed to deploy some code.

This is a continuation of my article on getting started with AWS Lambda.

See also my Github repo.

What you will need

  • the AWS CLI
  • some Python code
  • an AWS . . .

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July 16, 2017

POSTing images to pure F# Web API 2.0

Getting the multi-part form data out of your web API requests

Why am I doing this?

I have a REST API that I built with the Pure F# Web API templates. Mostly my REST API was just designed to output and process JSON, but recently I needed to accept images.

The problem

I need to save some images, through my REST API, that are produced on another system. I need that system to . . .

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July 06, 2017

AWS Lambda and S3: a quick and dirty tutorial

Figure out the basics without tearing your hair out

Why am I doing this?

I wanted to setup an example of how to use AWS Lambda with S3 for two reasons: do a talk on using these features at the Tucson Python Meetup (TuPLE), and help a a TuPLE member get started with a prototype for his (totally awesome) radiology image-processing functions.

BTW: this is a great reason to go . . .

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July 03, 2017

A bit of Railway Oriented Programming with Coconut

Using Coconut/Python to build a pipeline with error handling

Why am I doing this?

I recently did a talk on Coconut at the Tucson Python Meetup (aka TuPLE). I mostly demoed the examples in the tutorial and the documentation, but I also came up with a way to do error handling like I do in F# with Railway Oriented Programming that I learned from F# for Fun and Profit.

You can find my . . .

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May 27, 2017

Welcome to the Research Bazaar

ResBaz Arizona

Silvrback blog image

The very first Research Bazaar in Arizona will be happening March 31 - April 1. We are trying to bring digital literacy to scientists and researchers. This means helping people learn basic programming skills, like python and the shell, more advanced skills like data visualization, virtual machines, high performance computing, source . . .

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March 25, 2017


Cover image credit:,0090,1,1,0,0,1