Making matplotlib scatter plots from dataframes in Python's pandas

PythonPandasServer Side ProgrammingProgramming

Using Pandas, we can create a dataframe and can create a figure and axes variable using subplot() method. After that, we can use the ax.scatter() method to get the required plot.

Steps

  • Make a list of the number of students.

  • Make a list of marks that have been obtained by the students.

  • To represent the color of each scattered point, we can have a list of colors.

  • Using Pandas, we can have a list representing the axes of the data frame.

  • Create fig and ax variables using subplots method, where default nrows and ncols are 1.

  • Set the “Students count” label using plt.xlabel() method.

  • Set the “Obtained marks” label using plt.ylabel() method.

  • To create a scatter point, use the data frame created in step 4. Points are students_count, marks and color.

  • To show the figure, use plt.show() method.

Example

from matplotlib import pyplot as plt
import pandas as pd

no_of_students = [1, 2, 3, 5, 7, 8, 9, 10, 30, 50]
marks_obtained_by_student = [100, 95, 91, 90, 89, 76, 55, 10, 3, 19]
color_coding = ['red', 'blue', 'yellow', 'green', 'red', 'blue', 'yellow', 'green', 'yellow', 'green']

df = pd.DataFrame(dict(students_count=no_of_students,
marks=marks_obtained_by_student, color=color_coding))

fig, ax = plt.subplots()

plt.xlabel('Students count')
plt.ylabel('Obtained marks')

ax.scatter(df['students_count'], df['marks'], c=df['color'])

plt.show()

Output

raja
Published on 17-Mar-2021 07:32:16
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