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Emacs AWS Glue PySpark Development Setup

1. Create a new developer endpoint

   • Specify $HOME/.ssh/jumphost.pub as your public key

2. Update $HOME/.ssh/config accordingly:

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import collections
import random


def iter_words(rows):
    return (
        s.strip() for row in rows for s in row.split(" ") if s.strip() != ""
    )

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“Through the night and day”

The Problem

• Never written a poem before

The Solution

• Make the computer generate a poem for me

How?

Markov Chain

• Wikipedia:

  	 A Markov chain is a stochastic model describing a sequence of possible events in which the probability of each event depends only on the state attained in the previous event.
      

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const assert = require("assert");
const Environment = require("./Environment");

const GlobalEnvironment = new Environment({
  null: null,

  true: true,
  false: false,

  VERSION: "0.1",

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#lang racket

(define set?
  (lambda (lat)
    (cond
      [(null? lat) #t]
      [(null? (cdr lat)) #t]
      [(eq? (car lat) (car (cdr lat))) #f]
      [else (and (set? (cons (car lat) (cdr (cdr lat))))
                 (set? (cdr lat)))])))

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What If?

@microamp

Preface: Syntax vs Semantics

• Syntax:

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#lang racket

(provide (all-defined-out))

;; definition of structures for MUPL programs - Do NOT change
(struct var  (string) #:transparent)  ;; a variable, e.g., (var "foo")
(struct int  (num)    #:transparent)  ;; a constant number, e.g., (int 17)
(struct add  (e1 e2)  #:transparent)  ;; add two expressions
(struct ifgreater (e1 e2 e3 e4)    #:transparent) ;; if e1 > e2 then e3 else e4
(struct fun  (nameopt formal body) #:transparent) ;; a recursive(?) 1-argument function

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#lang racket

(provide (all-defined-out))

;; 1
(define (sequence low high stride)
  (if (> low high)
      null
      (cons low (sequence (+ low stride) high stride))))

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(define-syntax unless
  (syntax-rules ()
    [(unless e1 e2 e3)
     (if (not e1) e2 e3)]
    [(unless e1 e2)
     (if (not e1) e2 #f)]))

(unless #t (/ 1 0) (+ 1 2 3 4)) ;; 10
(unless #t (/ 1 0)) ;; #f

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(define (pow1 x y)
  (if (zero? y)
      1
      (* x (pow1 x (- y 1)))))

(define pow2
  (lambda (x)
    (lambda (y)
      (if (zero? y)