How to visualize data in Python?

Practicing Coding Interview Questions in Python

Kirill Smirnov

Data Science Consultant, Altran

matplotlib

import matplotlib.pyplot as plt

scatter plot
histogram
boxplot

Dataset

import pandas as pd

diabetes = pd.read_csv('diabetes.csv')
diabetes = diabetes[[
    'n pregnant', 'plasma glucose', 'blood pressure', 'skin thickness',
    'serum insulin', 'bmi', 'age', 'test result']]
print(diabetes.head())

   n pregnant  plasma glucose  blood pressure  skin thickness  serum insulin   bmi  age test result
0           6           148.0            72.0            35.0            NaN  33.6   50    positive
1           1            85.0            66.0            29.0            NaN  26.6   31    negative
2           8           183.0            64.0             NaN            NaN  23.3   32    positive
3           1            89.0            66.0            23.0           94.0  28.1   21    negative
4           0           137.0            40.0            35.0          168.0  43.1   33    positive

Scatter plot

Create a scatter plot

import matplotlib.pyplot as plt

plt.scatter(
    diabetes['serum insulin'],
    diabetes['plasma glucose']
)
plt.show()

Scatter plot

Create a scatter plot

import matplotlib.pyplot as plt

plt.scatter(
    diabetes['serum insulin'],
    diabetes['plasma glucose']
)

plt.title('Plasma Glucose vs Serum Insulin')

plt.show()

Scatter plot

Create a scatter plot

import matplotlib.pyplot as plt

plt.scatter(
    diabetes['serum insulin'],
    diabetes['plasma glucose']
)

plt.title('Plasma Glucose vs Serum Insulin')

plt.xlabel('Serum Insulin')
plt.ylabel('Plasma Glucose')

plt.show()

Scatter plot

Histogram

Create a histogram

import matplotlib.pyplot as plt

plt.hist(diabetes['bmi'])

plt.title('Histogram of BMI index')

plt.xlabel('BMI index')
plt.ylabel('counts')

plt.show()

Histogram

Create a histogram

import matplotlib.pyplot as plt

plt.hist(diabetes['bmi'], bins=20)

plt.title('Histogram of BMI index')

plt.xlabel('BMI index')
plt.ylabel('counts')

plt.show()

Histogram

Boxplot

Create a boxplot

import seaborn as sns

sns.boxplot('test_result', 'bmi', data=diabetes)
plt.title('Boxplot of BMI index')

plt.show()

Boxplot

Create a boxplot

import seaborn as sns

sns.boxplot(
    x='test_result',
    y='bmi',
    data=diabetes
)
plt.title('Boxplot of BMI index')

plt.show()

Boxplot

Create a boxplot

import seaborn as sns

sns.boxplot(
    y='test_result',
    x='bmi',
    data=diabetes
)
plt.title('Boxplot of BMI index')

plt.show()

Boxplot

Let's practice!

Practicing Coding Interview Questions in Python