Dynamically serving a matplotlib image to the web using python

Question

This question has been asked in a similar way here but the answer was way over my head (I\'m super new to python and web development) so I\'m hoping there\'s a simpler way o

Answer 1

You should

• first write to a cStringIO object
• then write the HTTP header
• then write the content of the cStringIO to stdout

Thus, if an error in savefig occured, you could still return something else, even another header. Some errors won't be recognized earlier, e.g., some problems with texts, too large image dimensions etc.

You need to tell savefig where to write the output. You can do:

format = "png"
sio = cStringIO.StringIO()
pyplot.savefig(sio, format=format)
print "Content-Type: image/%s\n" % format
msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY) # Needed this on windows, IIS
sys.stdout.write(sio.getvalue())

If you want to embed the image into HTML:

print "Content-Type: text/html\n"
print """
...a bunch of text and html here...

...more text and html...
""" % sio.getvalue().encode("base64").strip()