germayneng

require(caret)

#load some data
data(USArrests)

### Prepare Data (postive observations)
# add a column to be the strata.  In this case it is states, it can be sites, or other locations
# the original data has 50 rows, so this adds a state label to 10 consecutive observations
USArrests$state <- c(rep(c("PA","MD","DE","NY","NJ"), each = 5))
# this replaces the existing rownames (states) with a simple numerical index

germayneng

R to python useful 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

germayneng

### 
### Thanks to Karl Broman http://kbroman.org/knitr_knutshell/pages/Rmarkdown.html

```{r global_options, include=FALSE}
rm(list=ls()) ### To clear namespace
library(knitr)
opts_chunk$set(fig.width=12, fig.height=8, fig.path='Figs/',
               echo=TRUE, warning=FALSE, message=FALSE)
```

germayneng

from tqdm import tqdm_notebook as tqdm
from joblib import Parallel, delayed
import time

import random

def func(x):
    time.sleep(random.randint(1, 10))
    return x

germayneng

# -*- coding: utf-8 -*-
import dash
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output
import pandas as pd
import sqlalchemy
import altair as alt
import io
from vega_datasets import data

germayneng

from scipy.spatial.distance import pdist, squareform
import numpy as np

from numbapro import jit, float32

def distcorr(X, Y):
    """ Compute the distance correlation function
    
    >>> a = [1,2,3,4,5]
    >>> b = np.array([1,2,9,4,4])

germayneng

# author: @Daniel_Abeles
# date:   18/12/2017

import asyncio
from aiohttp import ClientSession
from timeit import default_timer
import async_timeout


async def fetch_all(urls: list):

germayneng

#standardSQL
CREATE TEMPORARY FUNCTION geohashEncode(latitude FLOAT64, logitude FLOAT64, precision FLOAT64)
RETURNS STRING 
  LANGUAGE js 
  AS """
    var Geohash = {};
    /* (Geohash-specific) Base32 map */
    Geohash.base32 = '0123456789bcdefghjkmnpqrstuvwxyz';
    
    lat = Number(latitude);

germayneng

import json
from pyspark.sql.types import *

# Define the schema
schema = StructType(
    [StructField("name", StringType(), True), StructField("age", IntegerType(), True)]
)

# Write the schema
with open("schema.json", "w") as f:

germayneng

import numpy as np
import multiprocessing
from joblib import Parallel, delayed
from scipy.spatial.distance import pdist, squareform

def _dcorr(y, n2, A, dcov2_xx):
    """Helper function for distance correlation bootstrapping.
    """
    # Pairwise Euclidean distances
    b = squareform(pdist(y, metric='euclidean'))