Save multiple matplotlib figures in single PDF file using Python

Last Updated : 07 Nov, 2022

In this article, we will discuss how to save multiple matplotlib figures in a single PDF file using Python. We can use the PdfPages class’s savefig() method to save multiple plots in a single pdf. Matplotlib plots can simply be saved as PDF files with the .pdf extension. This saves Matplotlib-generated figures in a single PDF file named Save multiple plots as PDF.pdf in the current working directory.

Installation

pip install matplotlib

Stepwise Implementation

To come up with a solution, we will follow a few steps.

Step 1: Import necessary files.

Python3

from matplotlib import pyplot as plt 
from matplotlib.backends.backend_pdf import PdfPages

Step 2: Set up the figure size and adjust the padding between and around the subplots.

Python3

plt.rcParams["figure.figsize"] = [7.00, 3.50] 
plt.rcParams["figure.autolayout"] = True

Step 3: We will consider 3 plots, so let’s name them fig1, fig2, and fig3 using plt.figure().

Python3

fig1 = plt.figure() 
fig2 = plt.figure() 
Fig3 = plt.figure()

Step 4: Plot the first line using the plt.plot() method.

Python3

plt.plot([17, 45, 7, 8, 7], color='orange') 
plt.plot([13, 25, 1, 6, 3], color='blue') 
plt.plot([22, 11, 2, 1, 23], color='green')

Step 5: Create a function to save multiple images in a PDF file let’s say save_image().

Python3

def save_image(filename): 
    
    # PdfPages is a wrapper around pdf  
    # file so there is no clash and 
    # create files with no error. 
    p = PdfPages(filename) 
      
    # get_fignums Return list of existing 
    # figure numbers 
    fig_nums = plt.get_fignums()   
    figs = [plt.figure(n) for n in fig_nums] 
      
    # iterating over the numbers in list 
    for fig in figs:  
        
        # and saving the files 
        fig.savefig(p, format='pdf')  
          
    # close the object 
    p.close()   

Complete Code

Python3

import matplotlib 
from matplotlib import pyplot as plt 
from matplotlib.backends.backend_pdf import PdfPages 
  
# customizing runtime configuration stored 
# in matplotlib.rcParams 
plt.rcParams["figure.figsize"] = [7.00, 3.50] 
plt.rcParams["figure.autolayout"] = True
  
fig1 = plt.figure() 
plt.plot([17, 45, 7, 8, 7], color='orange') 
  
fig2 = plt.figure() 
plt.plot([13, 25, 1, 6, 3], color='blue') 
  
Fig3 = plt.figure() 
plt.plot([22, 11, 2, 1, 23], color='green') 
  
  
def save_image(filename): 
    
    # PdfPages is a wrapper around pdf  
    # file so there is no clash and create 
    # files with no error. 
    p = PdfPages(filename) 
      
    # get_fignums Return list of existing  
    # figure numbers 
    fig_nums = plt.get_fignums()   
    figs = [plt.figure(n) for n in fig_nums] 
      
    # iterating over the numbers in list 
    for fig in figs:  
        
        # and saving the files 
        fig.savefig(p, format='pdf')  
      
    # close the object 
    p.close()   
  
# name your Pdf file 
filename = "multi_plot_image.pdf"  
  
# call the function 
save_image(filename)   

Output:

Now after you run the code you can see on your local directory that a pdf containing all three plots will be saved in a pdf named “multi_plot_image.pdf”.