Nischal Shrestha nischalshrestha

R to python data wrangling snippets

The dplyr package in R makes data wrangling significantly easier. The beauty of dplyr is that, by design, the options available are limited. Specifically, a set of key verbs form the core of the package. Using these verbs you can solve a wide range of data problems effectively in a shorter timeframe. Whilse transitioning to Python I have greatly missed the ease with which I can think through and solve problems using dplyr in R. The purpose of this document is to demonstrate how to execute the key dplyr verbs when manipulating data using Python (with the pandas package).

dplyr is organised around six key verbs:

Algorithmic Audit: QII

A big moving company gets so many applications that it has started using an automated algorithm to decide who to hire. You have been called in as an independent consultant to determine if the hiring algorithm is biased against women. The algorithm is proprietary so you cannot access its source code. Instead, you will learn how to perform an algorithmic audit to measure potential biases.

In this activity, you will edit the influence.py module.

Applicant Data

Each applicant's data is stored as a list with five elements. Each element is a string representing a different attribute:

	;; This code is AWFUL and I'm sorry.

	;; idea from http://stackoverflow.com/a/23718676/415518
	;; This works after I added the `concat`!
	(define permutations
	(lambda (ls)
	(cond
	[(null? ls) '(())]
	[(equal? (length ls) 1) `((,(car ls)))]
	[(equal? (length ls) 2)

	#lang racket

	;; A solver for the following puzzle:
	;; Given 5 integers a, b, c, d, and e,
	;; find an expression that combines a, b, c, and d with arithmetic operations (+, -, *, and /) to get e.

	(require srfi/1)

	(define ops '(+ - * /))

	/*<?php
	///public class PhpJava { public static void main(String[] args) { System.out.printf("/%s",
	//\u000A\u002F\u002A
	class PhpJava {
	static function main() {
	echo(//\u000A\u002A\u002F
	"Hello World!");
	}}
	//\u000A\u002F\u002A
	PhpJava::main();

	#install.packages("jsonlite")
	library(jsonlite)
	#install.packages("httpuv")
	library(httpuv)
	#install.packages("httr")
	library(httr)

	# Can be github, linkedin etc depending on application
	oauth_endpoints("github")

	{
	// Evaluate file in the open SublimeREPL.
	// Depends on you creating the Packages/User/EvalInREPL.sublime-macro file.
	{ "keys": ["super+r"], "command": "run_macro_file", "args": { "file": "Packages/User/EvalInREPL.sublime-macro" },
	"context": [
	{ "key": "selector", "operator": "equal", "operand": "source.elm" }
	]
	},

	// Reindent selection on tab

	---
	title: "Escaping R Code in RMarkdown Paramaters"
	author: "Alex Axthelm"
	date: "6/23/2017"
	output: html_document
	params:
	unescaped_add: 1 + 1
	unescaped_fun: rnorm(10)
	escaped_add: !r 1 + 1
	escaped_fun: !r rnorm(10)

	import numpy as np
	from scipy.io.wavfile import write
	from math import pi, sin, floor
	from fractions import gcd
	from UtilityFunctions import *
	class SoundGenerator():

	# Constants
	def __init__(self, waveType = "Sine", frequency = 500, amplitude = 1.0, duration = 5):

	import requests

	base_url = 'https://api.github.com'


	def get_all_commits_count(owner, repo, sha):
	first_commit = get_first_commit(owner, repo)
	compare_url = '{}/repos/{}/{}/compare/{}...{}'.format(base_url, owner, repo, first_commit, sha)

	commit_req = requests.get(compare_url)