crosstyan

#! /usr/bin/env python
from turtle import circle
import cv2
import sys
import numpy as np
import typing
from typing import Tuple
import collections

# See also

crosstyan

#include <stdio.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>

#define REP(x, n) for (int x = 0; x < n; x++)
#define REP1(x, n) for (int x = 1; x <= n; x++)
#define NELEM(a) (sizeof(a)/sizeof(a[0]))

struct test_t {

crosstyan

Mongo/Docker Cheatsheet

To download the latest image:

$ docker pull mongo:latest

To run a mongo container with detached mode(-p) and with ports mapped (-p 27017-27017:27017-27019) and named (--name mongodb):

$ docker run -d -p 27017-27019:27017-27019 --name mongodb mongo:latest

crosstyan

Deadsnakes python 3.9 on Ubuntu 18.04 LTS

NOTE: Recently switched back to using pyenv so I can run multiple python versions without losing my mind. It only takes a few minutes to set up, but provides the flexibility I need without making things too complicated. See my gist, Manage python versions on Linux with pyenv for more.

The deadsnakes PPA make the latest stable versions of python available on Ubuntu 18.04 LTS (3.9 is already in the official apt repo for 20.04). I now find it preferable to installing from source.

The following was tested on a Ubuntu 18.04.5 LTS desktop with python 3.6.9 as the system python version ("python3").

The latest python available from deadsnakes as of July, 2021 is 3.9.6.

Prerequisites

crosstyan

Ring handler a function which accepts a request (map) and returns a response (map).

Ring middleware

function (handler, &args -> function(request -> response) because it is a closure handler and &args are in scope within the returned handler function.

a function which accepts a "next handler" (the next handler in the chain) + any extra arguments and returns a handler (function), which will accept a request and return a response.

crosstyan

import asyncio

class EchoClientProtocol:
    def __init__(self, message, loop):
        self.message = message
        self.loop = loop
        self.transport = None

    def connection_made(self, transport):
        self.transport = transport

crosstyan

;; in 1.0a4 no need of bracket
(import numpy  :as np
        pandas :as pd
        random      [random]
        functools   [reduce]
        seaborn           :as sns
        matplotlib.pyplot :as plt
        scipy.stats [norm]
        os          [listdir])

crosstyan

crosstyan

(defproject udp-server "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "EPL-2.0 OR GPL-2.0-or-later WITH Classpath-exception-2.0"
            :url "https://www.eclipse.org/legal/epl-2.0/"}
  :dependencies [[org.clojure/clojure "1.10.3"]
                 [aleph "0.4.6"]
                 [org.clojure/core.match "1.0.0"]]
  :repl-options {:init-ns udp-server.core})

crosstyan

(defrecord Tree [left elm right])

(defprotocol Monoid
   (append [a b] )
   (identity [a] ))

(defprotocol Foldable
  (foldl [l f i])
  (mfirst [l]))