Python-based tool to quickly view data

html, data, visualization
pip install fastex==0.0.2


fex - a simple, fast data explorer

Ever have a pile of data (stored as JSON objects) that you want to quickly visualize and scroll through? Here's a simple package that will let you do just that. Fex just needs your data and (optionally) an HTML template file that specifies how to render that single object.


# from git repo
git clone
pip install -e .

# OR from PIP
pip install fastex


Fex assumes that your data is formatted as .jsonl: each line is simply its own JSON object. For example, consider the following data.

{"id": 0, "title": "Test 1", "messages": [{"user": "A", "msg": "Hi"}, {"user": "B", "msg": "Hello! How's it going?"}, {"user": "A", "msg": "Good!"}]}
{"id": 1, "title": "Test 2", "messages": [{"user": "B", "msg": "I need help!"}, {"user": "A", "msg": "Uh oh! What happened?"}, {"user": "B", "msg": "Sorry, false alarm, everything is ok."}]}

Running fex view will launch a web server that visualizes each of these objects using a template rendered with Jinja. Fex provides a default visualization is already prettier than staring at JSON:


The real power of Fex comes from being able to quickly hack a template that you find more useful. For example, the above data represents a chat transcript and it would be much nicer to visualize it as such. To do so, first run fex init, which will copy over a template.html file that you can edit. Using the example template produces the following result:



Notice the navbar at the top allows you to quickly toggle through input.

Frequently asked questions

  • Q: Can I use paths that are not data.jsonl or template.html?
    • A: Yes! Use the options -i or --input to specify the data file and -t or --template to specify the template file: fex view -i mydata.jsonl -t mytemplate.html.
  • Q: Can I use a custom port?
    • A: Yes! Use the options -p or --port: fex view -p 9000.