Robert James Metcalfe Blog

Python Matplotlib Chart Sharing Tutorial

Our Python Matplotlib More Involved Charts Tutorial‘s Python Matplotlib module accessing PHP web application is full of URLs featuring ? and & argumented parts via it’s use of an HTML form method=GET paradigm. As such, it is straightforward to add some …

• email … or …
• SMS

… based “a” link means to sharing user defined Python Matplotlib module based chart data with recipients …

<?php echo ”

<a target=_blank onclick=\"document.getElementById('aemailsms').href='mailto:?subject=" . str_replace('+','%20',urlencode($chartname)) . "&body=' + encodeURIComponent(document.URL); document.getElementById('aemailsms').click();\" id=aemail title=Email>&#128231;</a> <a target=_blank onmouseover=\"if (smsee.length == 0) { smsee=prompt('Please enter SMS number to send to.', ''); if (smsee == null) { smsee=''; } else { document.getElementById('aemailsms').href='sms:' + smsee + '&body=' + encodeURIComponent(document.URL); document.getElementById('aemailsms').click(); } }\" id=asms title=SMS>&#128223;</a>
<a target=_top id=aemailsms href='mailto:' style='display:none;'>Email or SMS</a>

“; ?>

We did most of the work, yesterday, on a short foray into some CSS styling, on this project, via …

<?php echo ”

<style>
input[type=submit]:focus { border: 4px dotted green; }
input[type=submit] { border-radius: 20px; padding: 7 7 7 7; }
input[type=text] { width: 98%; border-radius: 120px; padding: 7 7 7 7; background-color: #fafafa; }
textarea { width: 98%; border-radius: 5px; padding: 7 7 7 7; background-color: #fafafa; }
select { width: 60px; border-radius: 6px; background-color: #f0f0f0; }
</style>

“; ?>

… where, also, in the changed pie_chart_python.php PHP Python Matplotlib Chart Interfacing web application you can also try below, we decided textarea elements should replace those input type=text textboxes presented when the form has the device screen to itself. Those textarea elements have a great feature where their resizing talents are infectious when a few textarea elements are adjacent to each other!

Previous relevant Python Matplotlib More Involved Charts Tutorial is shown below.

Python Matplotlib More Involved Charts Tutorial

Further to yesterday’s Python Matplotlib Yet More Charts Tutorial‘s simpler Python Matplotlib module chart type interfacings today it was more involved with the new …

• Sankey Chart
• Bubble Chart
• Timeline Chart
• Histogram Chart

… in …

• the changed pie_chart_python.py Python … supervised by …
• the changed pie_chart_python.php PHP Python Matplotlib Chart Interfacing web application you can also try below

We hope you start trying these charts out for yourself!

Previous relevant Python Matplotlib Yet More Charts Tutorial is shown below.

Python Matplotlib Yet More Charts Tutorial

We’ve had a day of grappling with reality sizing up yesterday’s Python Matplotlib More Charts Tutorial‘s …

… interesting in that the difference between the presentation of various chart types amounts to a couple of lines of Python code, in essence …

… assertion, and yes, as with today’s changes, some Python Matplotlib module chart type interfacings do only involve a couple of lines of code that change, and this amounts to today’s forward progress, but some other chart interfacings are more involved and we’ll be trying into the future … doh!

Today, we, in addition to Pie Chart and Bar Chart and Column Chart interfacing, are introducing Matplotlib module chart type interfacing to …

• Scatter Chart
• Pseudocolour Chart
• Hexbin Chart
• Stairs Chart
• Stem Chart

… in …

• the changed pie_chart_python.py Python … supervised by …
• the changed pie_chart_python.php PHP Python Matplotlib Chart Interfacing web application you can also try below

Previous relevant Python Matplotlib More Charts Tutorial is shown below.

Python Matplotlib More Charts Tutorial

We doubt you’ll meet many programmers not interested in “peer to peer” software suite arrangements. Thinking about Python Matplotlib module, of course, “peer to peer” becomes interesting in that the difference between the presentation of various chart types amounts to a couple of lines of Python code, in essence.

With that in mind, we think to rewrite wholly fleshed out new code file pairs consisting of …

• a Python code file specializing in creation of a display of a particular Matplotlib module chart type … supervised by a …
• PHP supervising code file specializing in helping Python code file creation of a display of a particular Matplotlib module chart type

… for any one newly considered Matplotlib module chart type sounds like “too much hard work”. Why not add intelligence to that original Pie Chart code file pairing Python and PHP set and work off that? We came up with this idea, and it came to fruition.

And so, that is the long answer to yesterday’s question as to whether our …

strange idea

… would work?! The short answer …

Yes … the strange idea worked

… in the new workflow to getting up a new Matplotlib module chart type into the mix of our “peer to peer” web application software suite …

1. clone these two crontab records …
   
ksh -c 'for i in `find /home/rjmprogr/public_html/Python -name "piechartpython_*.py"`; do /usr/bin/python3 $i ${i##*/} /home/rjmprogr/public_html/Python/ ; done'
ksh -c 'for i in `find /home/rjmprogr/public_html/Python -name "piechartpython_*.py"`; do rm -f "$i"; done'

ksh -c 'for i in `find /home/rjmprogr/public_html/Python -name "plot_*.png" -mmin +122`; do rm -f "$i"; done'
ksh -c 'for i in `find /home/rjmprogr/public_html/Python -name "output_image_*.png" -mmin +122`; do rm -f "$i"; done'

   … to new ones, for the example of a Column Chart …
   
ksh -c 'for i in `find /home/rjmprogr/public_html/Python -name "columnchartpython_*.py"`; do /usr/bin/python3 $i ${i##*/} /home/rjmprogr/public_html/Python/ ; done'
ksh -c 'for i in `find /home/rjmprogr/public_html/Python -name "columnchartpython_*.py"`; do rm -f "$i"; done'


2. make the coding changes … as per …
   the changed pie_chart_python.py Python … brought in a new Bar Chart …
   the changed pie_chart_python.php PHP … helped bring in a new Bar Chart
   … but then, thinking on it …
   the changed pie_chart_python.py Python … brought in new Column and Bar Charts (in their traditional guises) …
   the changed pie_chart_python.php PHP … helped bring in new Column and Bar Charts (in their traditional guises)
3. and then … yay!!!! … the time saver … Linux web server command line soft links to the rescue again …
   
cd /home/rjmprogr/public_html/Python
ln -s pie_chart_python.py bar_chart_python.py
ln -s pie_chart_python.php bar_chart_python.php
ln -s pie_chart_python.py column_chart_python.py
ln -s pie_chart_python.php column_chart_python.php


   … to add onto the existant Matplotlib module Pie Chart coding, as of yesterday’s Python Matplotlib Pie Chart Labels Tutorial, interfacing now for Matplotlib module Bar Charts and Column Charts, where the logic for the new ++Bar ChartColumn ChartPie Chart dropdown “peer to peer” links all happening via …

   file naming conventions

   … getting both Python and PHP to code differentiate chart types via what appears as the action URL/file name on the address bar/command line.

   Feel free, as such, to try the Pie Chart⁺⁺ (now public) web application you can also try below.

   ---

   Previous relevant Python Matplotlib Pie Chart Labels Tutorial is shown below.

   

   Python Matplotlib Pie Chart Labels Tutorial

   Today, further to yesterday’s Python Matplotlib Pie Chart PHP Crontab Tutorial‘s Pie Chart via Python Matplotlib “guinea pig” phase, fleshing out Pie Chart labelling …

   … begging the question …

   Guinea pig to what?

   Do you cav^ye in?! Chortle, chortle. Well, our answer is …

   Cater for lots of other chart types Python Matplotlib can help interface to.

   … and we have a bit of a strange idea we want to try regarding this, while today’s second “not so strange” task preparatory work was to “abstract” the term “Pie Chart” and associated phrases out of being hardcodings to be a derivative of what URL is showing in the web browser address bar. Even if our “strange idea” disappoints, and we’ll let you know tomorrow, we think, we’d want to embark on this genericization anyway, the Earth being the distance away from Mars and Venus the way it is. As such …

   • the changed pie_chart_python.py Python … called via HTML form of …
   • the changed pie_chart_python.php PHP Pie Chart (now public) web application you can also try below

   … are definitely worth a peruse.

   ---

   Previous relevant Python Matplotlib Pie Chart PHP Crontab Tutorial is shown below.

   

   Python Matplotlib Pie Chart PHP Crontab Tutorial

   Onto yesterday’s Python Matplotlib Pie Chart Primer Tutorial‘s work …

   • further to local Apache/PHP web server, like MAMP, PHP understanding and supervising a Python Matplotlib module based Pie Chart web application … today …
   • extending that PHP meets Python theme on the public RJM Programming we involve …
     1. updated PHP … to suit the use of …
     2. crontab …
        
ksh -c 'for i in `find /home/rjmprogr/public_html/Python -name "piechartpython_*.py"`; do /usr/bin/python3 $i ${i##*/} /home/rjmprogr/public_html/Python/ ; done'
ksh -c 'for i in `find /home/rjmprogr/public_html/Python -name "piechartpython_*.py"`; do rm -f "$i"; done'
ksh -c 'for i in `find /home/rjmprogr/public_html/Python -name "plot_*.png" -mmin +122`; do rm -f "$i"; done'
ksh -c 'for i in `find /home/rjmprogr/public_html/Python -name "output_image_*.png" -mmin +122`; do rm -f "$i"; done'

        … means to run Python code where new arguments add image file folder and IP address personalization parts so that users do not stumble on other user Pie Chart specifications

   … all still dealing with a minimalist Pie Chart we’ll add complexity to into the future with …

   • the changed pie_chart_python.py Python … called via HTML form of …
   • the changed pie_chart_python.php PHP Pie Chart (now public) web application you can also try below

   ---

   Previous relevant Python Matplotlib Pie Chart Primer Tutorial is shown below.

   

   Python Matplotlib Pie Chart Primer Tutorial

   We’re off on a new discovery tour regarding …

   • Python … as a programming language, and it’s module …
   • Matplotlib

   … starting down this road with a simple …

   • command line Pie Chart application … Python pie_chart_python.py (superceeding this) …
     
# pie_chart_python.py
# September - 2026
# RJM Programming
# Thanks to https://www.w3schools.com/python/default.asp

import os
import matplotlib

# Set backend to Agg before importing pyplot
matplotlib.use('Agg')

import matplotlib.pyplot as plt
import matplotlib.image as mpimg

import numpy as np
#import plotly.express as px
from PIL import Image

nums = []
sofar = 0

if len(nums) <= 0:
while sofar < 100:
print(f"Enter your percentage value regarding a pie chart where so far {sofar} has already been allocated.")
anum = input()
nums.append(int(anum))
sofar += int(anum)

y = np.array(nums)

fig, ax = plt.subplots()

ax.pie(y)

fig.savefig("plot.png")

# 1. Load the image
img = mpimg.imread('plot.png')

# 2. Process or manipulate the image (Optional)
# For example, let's look at the shape or apply changes
#print(f"Image shape: {img.shape}")

# 3. Create the plot without displaying it
plt.imshow(img)
plt.axis('off') # Hide axis lines and labels

# 4. Save the result to a file instead of showing it
plt.savefig('output_image.png', bbox_inches='tight', pad_inches=0)
plt.close()

# Open the PNG image file
#with Image.open("plot.png") as img:
# Display the image using your system's default viewer
#img.show()

# Optional: Load the data into memory so you can safely close the file
#img.load()

exit()

     … and …
   • working on our local Apache/PHP MAMP web server (only, so far, the reason being our public web server has no graphical $DISPLAY existant, and so the plt.show() Python codeline cannot be used, so we need to think more on integrations there) … PHP pie_chart_python.php …
     
<?php
// pie_chart_python.php
// RJM Programming - September, 2026
if (php_sapi_name() === 'cli') {
$command = '/usr/local/bin/python3 ' . dirname(__FILE__) . DIRECTORY_SEPARATOR . 'piechartpython.py'; // Your command
if (1 == 1) {
exec($command);
} else {
// Open the process pointer for reading
$handle = popen($command, 'r');

if ($handle) {
// Read and output the buffer until the end of the file
while (!feof($handle)) {
echo fread($handle, 2048);
flush(); // Send it to the browser immediately
}
pclose($handle);
}
}
exit;
} else if (strpos(str_replace('?','',$_SERVER['QUERY_STRING']), '&') === false) {
$waspy=file_get_contents(dirname(__FILE__) . DIRECTORY_SEPARATOR . 'pie_chart_python.py');
if (strpos($waspy, "nums = []") !== false) {
if (isset($_GET['array'])) {
file_put_contents(dirname(__FILE__) . DIRECTORY_SEPARATOR . 'piechartpython.py', str_replace("nums = []","nums = [" . str_replace('+',' ',urldecode($_GET['array'])) . "]",$waspy));
}
}
//exec('php ' . dirname(__FILE__) . DIRECTORY_SEPARATOR . 'pie_chart_python.php > /dev/null 2> /dev/null');
exec('cd ' . dirname(__FILE__) . DIRECTORY_SEPARATOR . ' ; /Applications/MAMP/bin/php/php7.4.33/bin/php -n ./pie_chart_python.php > /dev/null 2> /dev/null ; open ./plot.png');
sleep(3);
}
echo "<html><body style=\"background:url(./plot.png);background-repeat:no-repeat;background-size:contain;\"></body></html>";
?>


   … allowing a web browser address bar URL such as …

   
http://localhost:8888/pie_chart_python.php?array=12,5,1,68


   … working for us, here, locally, displaying a Pie Chart …

   

   … via our local Python³ Matplotlib modularized environment.

   Did you know?

   Your installer for Python modules is likely to be one of, for the example of matplotlib module …

   
pip install matplotlib


   … or …

   
pip3 install matplotlib


   … corresponding to whether command line …

   
python pie_chart_python.py


   … or …

   
python3 pie_chart_python.py


   … works for you at your local system command line.

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