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Asked: 2026-06-06T17:06:20+00:00

I am building a python based web server ( Yes, python is a bad

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I am building a python based web server ( Yes, python is a bad choice for web server, but this is the only choice I have There is another great choice for my purpose, e.g. PHP, but I am restricted to python )

I use ProtoVis for some data visualization. (a JavaScript based visualization tool)

The following piece of code works if I just copy and paste them into a test file and rename .html (provided that I have the protovis library extracted beside it)

If you want to try, get it here https://github.com/mbostock/protovis/zipball/v3.3.1

<html>
    <head>
        <title>Area Chart</title>
        <link type="text/css" rel="stylesheet" href="ex.css?3.2"/>
        <script type="text/javascript" src="protovis/protovis.js"></script>
        <style type="text/css">
        #fig {
            width: 430px;
            height: 225px;
        }
        </style>
    </head>
    <body>
    <div id="center">
    <div id="fig">
    <script type="text/javascript+protovis">
    
var data = pv.range(0, 10, .1).map(function(x) {
    return {x: x, y: Math.sin(x) + Math.random() * .5 + 2};
  });
    
/* Sizing and scales. */
var w = 400,
    h = 200,
    x = pv.Scale.linear(data, function(d) d.x).range(0, w),
    y = pv.Scale.linear(0, 4).range(0, h);

/* The root panel. */
var vis = new pv.Panel()
    .width(w)
    .height(h)
    .bottom(20)
    .left(20)
    .right(10)
    .top(5);

/* Y-axis and ticks. */
vis.add(pv.Rule)
    .data(y.ticks(5))
    .bottom(y)
    .strokeStyle(function(d) d ? "#eee" : "#000")
  .anchor("left").add(pv.Label)
    .text(y.tickFormat);

/* X-axis and ticks. */
vis.add(pv.Rule)
    .data(x.ticks())
    .visible(function(d) d)
    .left(x)
    .bottom(-5)
    .height(5)
  .anchor("bottom").add(pv.Label)
    .text(x.tickFormat);

/* The area with top line. */
vis.add(pv.Area)
    .data(data)
    .bottom(1)
    .left(function(d) x(d.x))
    .height(function(d) y(d.y))
    .fillStyle("rgb(121,173,210)")
  .anchor("top").add(pv.Line)
    .lineWidth(3);

vis.render();

    </script>
    </div>
    </div>
    </body>
</html>

However, if I return the above code in a baseHTTPserver, it does not seem to work. From my investigation, it seems that the library at "protovis/protovis.js" is not properly included.

if url[0] == "/chart":
    self.send_response(200)
    self.send_header("Content-type","text/html")
    self.end_headers()
    self.wfile.write(chart())
    return

where chart() function returns the lines above.

I am working under CentOS 6.2 with python 2.6, is there anything special I need to do in baseHTTPserver to include that javascript library that I am using? The same code worked fine with Apache + PHP where I simply echo them.

Any idea?

======================== Solution ========================

Unlike Apache+PHP, BaseHTTPServer will not just serve anything you put into that folder. You have to either do it yourself, as Matthew described, or serve protovis.js from a different server (could even be a SimpleHTTPServer running on a different port). – Vasiliy Faronov

See Matthew Adams’s instruction below

What I had to do to fix the problem was to add another method into do_GET() that handles the JavaScript file

if url[0] == "/protovis/protovis.js":
    f = open("protovis/protovis.js","rb")
    for each_line in f:
        self.wfile.write(each_line)
    return

which solves the problem.

Thank you all for the solution, I really appreciate it

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1 Answer

  1. Editorial Team

    Make sure that you are serving protovis/protovis.js using your BaseHTTPServer. Basically the browser will “see” the line <script type="text/javascript" src="protovis/protovis.js"></script> when it is reading the html output it gets, and then request that the server actually send the protovis/protovis.js file. I didn’t see the python code in that github download, so I can’t specifically show how to do this in the context of your code, but check out SimpleHTTPRequestHandler. Using that, you can add to the do_GET() method to have the server send protovis/protovis.js when it is requested (that is, when self.path is protovis/protovis.js).

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