Pandas Dataframe display on a webpage

Question

I am using Flask but this probably applies to a lot of similar frameworks.

I construct a pandas Dataframe, e.g.

@app.route('/analysis/<filename>')
def analysis(filename):
    x = pd.DataFrame(np.random.randn(20, 5))
    return render_template("analysis.html", name=filename, data=x)

The template analysis.html looks like

{% extends "base.html" %}
{% block content %}
<h1>{{name}}</h1>
{{data}}
{% endblock %}

This works but the output looks horrible. It doesn’t use linebreaks etc.
I have played with data.to_html() and data.to_string()
What’s the easiest way to display a frame?

Asked By: tschm

||

Source

Answer 1

The following should work:

@app.route('/analysis/<filename>')
def analysis(filename):
    x = pd.DataFrame(np.random.randn(20, 5))
    return render_template("analysis.html", name=filename, data=x.to_html())
                                                                # ^^^^^^^^^

Check the documentation for additional options like CSS styling.

Additionally, you need to adjust your template like so:

{% extends "base.html" %}
{% block content %}
<h1>{{name}}</h1>
{{data | safe}}
{% endblock %}

in order to tell Jinja you’re passing in markup. Thanks to @SeanVieira for the tip.

Answered By: MattDMo

Answer 2

Ok, I have managed to get some very nice results by now combining the hints I got here. In the actual Python viewer I use

@app.route('/analysis/<filename>')
def analysis(filename):
    x = pd.DataFrame(np.random.randn(20, 5))
    return render_template("analysis.html", name=filename, data=x)

e.g. I send the complete dataframe to the html template. My html template is based on bootstrap. Hence I can simply write

{% extends "base.html" %}
{% block content %}
<h1>{{name}}</h1>
{{ data.to_html(classes="table table-striped") | safe}}
{% endblock %}

There are numerous other options with bootstrap, check out here:
http://getbootstrap.com/css/#tables

Base.html is essentially copied from here
http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-xii-facelift

The next question is obviously how to plot such a frame. Anyone any experience with Bokeh?

Thank you both to Matt and Sean.

thomas

Answered By: tschm

Answer 3

You can use enaml-web to display and interact with pandas dataframes.

A few examples:

With filtering – https://github.com/frmdstryr/smd-search
Simple viewer – https://github.com/codelv/enaml-web/tree/master/examples/dataframe_viewer

Note: Interaction (sorting, filtering, etc…) requires a server with websocket support.

Answered By: frmdstryr

Answer 4

Iterating over the rows of a df

If you need to have the df in a format that can iterate over the rows in your html, then use to_dict(orient='records'), which produces a dict in a format:

‘records’ : list like [{column -> value}, … , {column -> value}]

That way you can use your own way of displaying the data in your html.
The sample code would now look like this:

Python code using flask

@app.route('/analysis/<filename>')
def analysis(filename):
    x = pd.DataFrame(np.random.randn(20, 5))
    return render_template("analysis.html", name=filename, data=x.to_dict(orient='records'))

HTML code with jinja

{% extends "base.html" %}
    {% block content %}
    <table class="table">
        <thead>
            <tr>
                <th scope="col">Column name 1</th>
                <th scope="col">Column name 2</th>
                <th scope="col">Column name 3</th>
            </tr>
        </thead>
        <tbody>
        {% for row in data %}
            <tr>
                <td>{{row['Column name 1']}}</td>
                <td>{{row['Column name 2']}}</td>
                <td>{{row['Column name 2']}}</td>
            </tr>
        {% endfor %}
        </tbody>
    </table>
    {% endblock %}

Answered By: Mark

Pandas Dataframe display on a webpage

Question:

Answers:

Iterating over the rows of a df

Python code using flask

HTML code with jinja