Creating Data Visualizations in Python

In this post, we will walk through how to make data visualizations using the Palmers penguins dataset.

Setting Up Our Analysis

First, we will import the libraries that are used to store the data and create the plots. Then, we will obtain the data from the Palmer penguins dataset.

import pandas as pd
from matplotlib import pyplot as plt
import seaborn as sns

# retrieve data set from web
url = "https://raw.githubusercontent.com/PhilChodrow/PIC16B/master/datasets/palmer_penguins.csv"
penguins = pd.read_csv(url)

Data Exploration

Here, we are looking at the first few rows of the penguins dataset so that we understand which features were recorded. For this tutorial, we will be comparing the body masses of the penguins across the three islands that they were measured on.

penguins.head()

	studyName	Sample Number	Species	Region	Island	Stage	Individual ID	Clutch Completion	Date Egg	Culmen Length (mm)	Culmen Depth (mm)	Flipper Length (mm)	Body Mass (g)	Sex	Delta 15 N (o/oo)	Delta 13 C (o/oo)	Comments
0	PAL0708	1	Adelie Penguin (Pygoscelis adeliae)	Anvers	Torgersen	Adult, 1 Egg Stage	N1A1	Yes	11/11/07	39.1	18.7	181.0	3750.0	MALE	NaN	NaN	Not enough blood for isotopes.
1	PAL0708	2	Adelie Penguin (Pygoscelis adeliae)	Anvers	Torgersen	Adult, 1 Egg Stage	N1A2	Yes	11/11/07	39.5	17.4	186.0	3800.0	FEMALE	8.94956	-24.69454	NaN
2	PAL0708	3	Adelie Penguin (Pygoscelis adeliae)	Anvers	Torgersen	Adult, 1 Egg Stage	N2A1	Yes	11/16/07	40.3	18.0	195.0	3250.0	FEMALE	8.36821	-25.33302	NaN
3	PAL0708	4	Adelie Penguin (Pygoscelis adeliae)	Anvers	Torgersen	Adult, 1 Egg Stage	N2A2	Yes	11/16/07	NaN	NaN	NaN	NaN	NaN	NaN	NaN	Adult not sampled.
4	PAL0708	5	Adelie Penguin (Pygoscelis adeliae)	Anvers	Torgersen	Adult, 1 Egg Stage	N3A1	Yes	11/16/07	36.7	19.3	193.0	3450.0	FEMALE	8.76651	-25.32426	NaN

Creating Plots

In order to compare the body masses across islands, we will use a boxplot, as it will allow us to see the median and the distribution of the body masses. The library that is used will be seaborn, and we will set Island as the x-axis and Body Mass as the y-axis. To make the plot easier to read, we will also set the hue to Island.

fig,ax=plt.subplots(figsize=(10,7)) 

# create boxplot
fgrid = sns.boxplot(x="Island",
            y="Body Mass (g)",
            hue = "Island", 
            data = penguins,
            width = 0.4,
            dodge=True,
           )

# make title
fgrid.set_title("Body Mass across Islands")

Text(0.5, 1.0, 'Body Mass across Islands')