Ryan Williams ryan-williams

Monoid

A monoid has two components:

`id` (or `empty`)

"make an instance from nothing"

0 (Unit => Int)
"" (Unit => String)
Nil (Unit => List[_])

NE Scala 2020: "online-only" post-mortem

2020-03-20

On Saturday we wrapped up the Northeast Scala Symposium: a community-run conference related to the Scala programming language.

Going "online-only" at the last minute

On Tuesday, having sold 170 tickets to a conference starting Thursday at a venue in DUMBO, we decided to go "online only".

It's possible we should have made the call earlier. As is, some ppl were able to cancel their travel plans, others had already traveled, and (seemingly most) others had canceled on their own (or their employers had done it on their behalf).

Col1 is the field that will be the "rows" index
Col2 is the column whose values will become the new columns
Col3 is any other column (assuming that other columns are always filled; .count() will only count cells where Col3 has a value)

df \
.groupby(['Col1', 'Col2']) \
[['Col3']] \
.count() \
.reset_index() \
.pivot('Col1', 'Col2', 'Col3')

First, install pyenv:

curl https://pyenv.run | bash

(docs)

Follow its parting instructions to make sure you have pyenv in your $PATH:

# Load pyenv automatically by adding
# the following to ~/.bashrc:

	#!/usr/bin/env bash
	python3 gist_dir.py "$@"

Ryan Williams ryan-williams

Monoid

id (or empty)

NE Scala 2020: "online-only" post-mortem

Going "online-only" at the last minute

`id` (or `empty`)