Why does this D3 code not produce any output in Jupyter Notebook?

题意：为什么这段D3代码在Jupyter Notebook中没有产生任何输出？

问题背景：

I followed this blog here and here's the code that I'm trying to run on my Jupyter Notebook - essentially a simple scatter plot from the iris dataset.

我按照这篇博客的内容操作，以下是我尝试在Jupyter Notebook中运行的代码——主要是使用iris数据集生成一个简单的散点图。

from IPython.core.display import display, HTML
from string import Template
import pandas as pd
import json, random

HTML('<script src="./d3.min.js"></script>')

filename = 'https://gist.githubusercontent.com/mbostock/3887118/raw/2e68ffbeb23fe4dadd9b0f6bca62e9def6ee9e17/data.tsv'
iris = pd.read_csv(filename,sep="\t")

iris_array_of_dicts = iris.to_dict(orient='records')

css_text = '''
.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.dot {
  stroke: #000;
}
'''

js_text_template = Template('''
var margin = {top: 20, right: 20, bottom: 30, left: 40},
// ****    width = 960 - margin.left - margin.right, ****
// ****    height = 500 - margin.top - margin.bottom; ****
    width = 720 - margin.left - margin.right,
    height = 375 - margin.top - margin.bottom;

var x = d3.scale.linear()
    .range([0, width]);

var y = d3.scale.linear()
    .range([height, 0]);

var color = d3.scale.category10();

var xAxis = d3.svg.axis()
    .scale(x)
    .orient("bottom");

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left");

// **** var svg = d3.select("body").append("svg") ****
var svg = d3.select("#$graphdiv").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

// **** d3.tsv("data.tsv", function(error, data) { ****
// ****  if (error) throw error; ****

var data = $python_data ;

  data.forEach(function(d) {
    d.sepalLength = +d.sepalLength;
    d.sepalWidth = +d.sepalWidth;
  });

  x.domain(d3.extent(data, function(d) { return d.sepalWidth; })).nice();
  y.domain(d3.extent(data, function(d) { return d.sepalLength; })).nice();

  svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis)
    .append("text")
      .attr("class", "label")
      .attr("x", width)
      .attr("y", -6)
      .style("text-anchor", "end")
      .text("Sepal Width (cm)");

  svg.append("g")
      .attr("class", "y axis")
      .call(yAxis)
    .append("text")
      .attr("class", "label")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", ".71em")
      .style("text-anchor", "end")
      .text("Sepal Length (cm)")

  svg.selectAll(".dot")
      .data(data)
    .enter().append("circle")
      .attr("class", "dot")
      .attr("r", 3.5)
      .attr("cx", function(d) { return x(d.sepalWidth); })
      .attr("cy", function(d) { return y(d.sepalLength); })
      .style("fill", function(d) { return color(d.species); });

  var legend = svg.selectAll(".legend")
      .data(color.domain())
    .enter().append("g")
      .attr("class", "legend")
      .attr("transform", function(d, i) { return "translate(0," + i * 20 + ")"; });

  legend.append("rect")
      .attr("x", width - 18)
      .attr("width", 18)
      .attr("height", 18)
      .style("fill", color);

  legend.append("text")
      .attr("x", width - 24)
      .attr("y", 9)
      .attr("dy", ".35em")
      .style("text-anchor", "end")
      .text(function(d) { return d; });

// **** }); ****

''')

html_template = Template('''
<style> $css_text </style>
<div id="graph-div"></div>
<script> $js_text </script>
''')

js_text = js_text_template.substitute({'python_data': json.dumps(iris_array_of_dicts),
                                       'graphdiv': 'graph-div'})
HTML(html_template.substitute({'css_text': css_text, 'js_text': js_text}))

The code runs without errors but doesn't display any output. I've also tried to use the display functionality but that still produces no results.

代码运行时没有错误，但没有显示任何输出。我也尝试使用display功能，但仍然没有结果。

What am I doing wrong? My assumption is that since this is an old blog post, Jupyter has moved past supporting Javascript this way and I have to use cell and line magics now but I'm not sure as I'm new to Javascript.

我做错了什么？我的猜测是，由于这是一篇较旧的博客文章，Jupyter已经不再以这种方式支持JavaScript，我现在必须使用单元格和行魔术（magic）命令，但我不确定，因为我是JavaScript的新手。

问题解决：

I have just tried and figured out the problem.

我刚刚尝试并找出了问题所在。

If you look at the console log, the browser do not interpret d3. To solve it add to your code.

如果你查看控制台日志，浏览器没有解释d3。为了解决这个问题，你需要在代码中添加一些内容。

<script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>

You will now see your nice plot

你现在将会看到你的漂亮图表

Here an exemple of update

这里有一个更新的例子

In [1]:
from IPython.core.display import display, HTML
from string import Template
import pandas as pd
import json, random

HTML('<script src="./d3.min.js"></script>')

filename = 'https://gist.githubusercontent.com/mbostock/3887118/raw/2e68ffbeb23fe4dadd9b0f6bca62e9def6ee9e17/data.tsv'
iris = pd.read_csv(filename,sep="\t")

iris_array_of_dicts = iris.to_dict(orient='records')

css_text = '''
.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.dot {
  stroke: #000;
}
'''

js_text_template = Template('''

var margin = {top: 20, right: 20, bottom: 30, left: 40},
// ****    width = 960 - margin.left - margin.right, ****
// ****    height = 500 - margin.top - margin.bottom; ****
    width = 720 - margin.left - margin.right,
    height = 375 - margin.top - margin.bottom;