wrgoldstein

Simple physics:

velocity = distance / time

momentum = mass x velocity

An analogy:

The distance traveled by a single developer in a set amount of time is "velocity"
The movement of the organization as a whole is "momentum" (the sum of individual velocities)
If you add more people but reduce velocity then momentum decreases (this is why small teams are sometimes more productive than big teams).

Sometimes in a large project you may have many scripts using the same python package, and want to upgrade that package for only some of them.

PIP makes this easy: install the older (or newer) version in its own directory, and import it explicitly.

pip install -r requirements-prev.txt --target prev

from prev import pandas as pd

	"""
	Elixir server that partially speaks the PG wire protocol. Run:

	```
	mix run psql_wire_protocol.exs
	```

	and run psql at a separate terminal prompt:

	```

	"""
	A cli to populate a local database with production
	data. Expects a companion file called tables.py to exist
	with the following structure:

	```python
	# tables.py

	# any tables that should be downloaded in their entirety
	small_tables = [

	g_poisson = fn lambda ->
	# generate poisson random variables according to
	# the Knuth method
	l = :math.exp(-lambda)
	Stream.unfold({0, 1}, fn
	{k, p} ->
	u = p * :random.uniform()
	{{k, u}, {k+1, u}}
	end)
	\|> Stream.drop_while(fn {k, p} -> p > l end)

	# imagine each of these is of the form {uuid, timestamp}
	# can definitely be refactored but wanted to learn about `Flow.emit_and_reduce/3`

	data = [
	{:a, 1},
	{:a, 2},
	{:b, 2},
	{:a, 5},
	{:a, 11},
	{:a, 12},

	# thanks https://git-scm.com/book/en/v2/Git-Basics-Git-Aliases
	git config --global alias.co checkout
	git config --global alias.br branch
	git config --global alias.ci commit
	git config --global alias.s status

	defmodule Exstuf do
	@doc """
	Illustration of the philosopher dining problem.

	Reimplementation of https://www.golangprograms.com/go-language/concurrency.html

	## Examples

	iex> Exstuf.start()
	for _ <- 1..5, do: :satisfied

	delete from schema.table using (
	select *,
	row_number() over (partition by id order by created_at desc) as row
	from schema.table
	) duplicates
	where table.id = duplicates.id
	and table.created_at = duplicates.created_at
	and row > 1