Python: Create a Box whisker plot

Box whisker plots are used in stats to graphically view the spread of a data set, as well as to compare data sets.

If you would like to follow along with this example, he is the data set: sensors

Using pandas, let’s load the data set

%matplotlib inline
import pandas as pd
import matplotlib as mp
import matplotlib.pyplot as plt

sensorDF = pd.read_excel("C:\Users\Benjamin\Documents\sensors.xlsx")

Our data set represents monthly readings taken from 4 sensors over the span of a year


We need to convert the dataframe to a list values for our box plot function.

To do this, first we need to flatten() our dataframe. The flatten() method places all the values from the dataframe into 1 list


Now let us chop the list into the for sensors represented by the rows in our dataframe


Finally, we need to make a list of these lists


I know that seemed like a lot, but you will spend more time cleaning and prepping data than any other task. It is just the nature of the job.

Let’s Plot

The code for creating a boxplot is now easy.


Let’s label our chart a little better now.