Mercury

Share your Python notebooks with others

Easily convert your Python notebooks into interactive web apps by adding parameters in YAML.

• Simply add YAML with a description of the parameters needed in the notebook.
• Share a notebook with others.
• Allow them to execute the notebook with selected parameters.
• You can decide to show or hide your code.
• Easily deploy to the server.

Mercury is a perfect tool to share your Python notebooks with non-programmers.

• You can turn your notebook into a web app. Sharing is as easy as sending them the URL to your server.
• You can add interactive input to your notebook by defining the YAML header. Your users can change the input and execute the notebook.
• You can hide your code to not scare your (non-coding) collaborators.
• Users can interact with notebook and save results.
• You can share a notebook as a web app with multiple users - they don't overwrite the original notebook.

Example

Notebook with YAML config

The YAML config is added as the first raw cell in the notebook.

Web Application from Notebook

The web app is generated from the notebook. Code is hidden (optional). User can change parameters, execute notebook with the Run button, and save results with the Download button.

Check our demo

The demo with several example notebooks is running at http://mercury.mljar.com (running on AWS EC2 t3a.small instance). No need to register.

The demo is running at Heroku free dyno http://mercury-demo-1.herokuapp.com (with several notebooks-apps). No need to register. (if dyno is sleeping and notebooks are not loaded, please refresh it and wait a little)

Share mutliple notebooks

You can share as many notebooks as you want. There is a gallery with notebooks in the home view of the Mercury. You can select any notebook by clicking the Open button.

Convert Notebook to web app with YAML

You need to add YAML at the beginning of the notebook to be able to run it as a web application in the Mercury. The YAML configuration should be added as a Raw cell in the notebook. It should start and end with a line containing "---". Below examples of how it should look like in the Jupyter Notebook and Jupyter Lab:

Allowed parameters in YAML config:

• title - string with a title of the notebook. It is used in the app sidebar and the gallery view.
• author - string with a author name (optional).
• description - string describing the content of the notebook. It is used in the gallery view.
• show-code - can be True or False. Default is set to True. It decides if the notebook's code will be displayed or not.
• show-prompt - can be True or False. Default is set to True. If set to True prompt information will be displayed for each cell in the notebook.
• params - the parameters that will be used in the notebook. They will be displayed as interactive widgets in the sidebar. Each parameter should have a unique name that corresponds to the variable name used in the code.

Define widget with YAML

Widget name is a variable name

Definition of the widget (in params) starts with the widget name. It will correspond to the variable in the code. The name should be a valid Python variable.

Widget input type

The next thing is to select the input type. It can be: text, slider, range, select, checkbox, numeric, file.

Widget label

For each input we need to define a label. It will be a text displayed above (or near) the widget.

Widget default value

You can set a default widget by setting the value. The format of the value depends on the input type:

• for text a value should be a string, example value: example text,
• for slider a value should be a number, example: value: 5,
• for range a value should be a list with two numbers, example value: [3,6],
• for select with mutli: False a value should be a string, example value: hey,
• for select with multi: True a value should be a list of strings, example value: [cześć, hi, hello],
• for checkbox a value should be a boolean (True or False), example: value: True,
• for numeric a value should be a number, example: value: 10.2.
• for file a value is not needed.

The rest of the parameters depend on the widget input type.

Text

Additional parameters:

• rows - the number of rows in the text area (default is set to 1),

Example YAML:

params:
    my_variable:
        input: text
        label: This is text label
        value: some text
        rows: 2

Slider

Additional parameters:

• min - the minimum value for the slider (default is set to 0),
• max - the maximum value for the slider (default is set to 100).

Example YAML:

params:
    my_variable:
        input: slider
        label: This is slider label
        value: 5
        min: 0
        max: 10

Range

Additional parameters:

• min - the minimum value for the slider (default is set to 0),
• max - the maximum value for the slider (default is set to 100).

Example YAML:

params:
    range_variable:
        input: range
        label: This is range label
        value: [3,6]
        min: 0
        max: 10

Select

Additional parameters:

• multi - a boolean value that decides if the user can select several options (default is set to False).
• choices - a list with available choices.

Example YAML:

params:
    select_variable:
        label: This is select label
        input: select
        value: Cześć
        choices: [Cześć, Hi, Hello]
        multi: False

Checkbox

There are no additional parameters.

Example YAML:

params:
    checkbox_variable:
        label: This is checkbox label
        input: checkbox
        value: True

Numeric

Additional parameters:

• min - a minimum allowed value (default set to 0),
• max - a maximum allowed value (default set to 100),
• step - a step value (default set to 1).

params:
    numeric_variable:
        label: This is numeric label
        input: numeric
        value: 5.5
        min: 0
        max: 10
        step: 0.1

File

Additional parameters:

• maxFileSize - a maximum allowed file size (default set to 100MB). The file size should be defined as a string with MB or KB at the end.

params:
    filename:
        label: This is file label
        input: file
        maxFileSize: 1MB

The uploaded file name will be passed to the notebook as a string. The uploaded file will be copied to the same directory as the notebook. After notebook execution, the uploaded file will be removed.

Full example YAML

---
title: My notebook
author: Piotr
description: My first notebook in Mercury
params:
    my_variable:
        label: This is slider label
        input: slider
        value: 5
        min: 0
        max: 10
    range_variable:
        label: This is range label
        input: range
        value: [3,6]
        min: 0
        max: 10    
    select_variable:
        label: This is select label
        input: select
        value: Cześć
        choices: [Cześć, Hi, Hello]
        multi: False
    checkbox_variable:
        label: This is checkbox label
        input: checkbox
        value: True
    numeric_variable:
        label: This is numeric label
        input: numeric
        value: 5.5
        min: 0
        max: 10
        step: 0.1
---

Widgets rendered from above YAML config:

Use variables in the code

To use variables in the code simply define the variable with the same name as the widget name. You can also assign the same value as defined in YAML. Please define all variables in one cell (it can be below the cell with YAML config).

When the user interacts with widgets and clicks the Run button, the code with variables will be updated with user selected values.

Example:

Output files

You can easily create files in your notebook and allow your users to download them.

You need to define an output directory in YAML header and in variables add variable with output directory name.

The example notebook:

1. The first RAW cell.

title: My app
description: App with file download
params:
    output_dir:
        output: dir

2. The next cell should have a variable containing the directory name. The variable should be exactly the same as in YAML. This variable will have assigned a new directory name that will be created for your user during notebook execution. Please remember to define all variables that are interactive in Mercury in one cell, just after the YAML header (that's the only requirement to make it work, but very important).

output_dir = "example_output_directory"

3. In the next cells, just produce files to the output_dir:

import os
with open(os.path.join(output_dir, "my_file.txt"), "w") as fout:
    fout.write("This is a test")

In the Mercury application, there will be additional menu in the top with Output files button. Please click there to see your files. Each file in the directory can be downloaded.

Welcome message

There is an option to set a custom welcome message. Like in the example screenshot below.

The custom welcome message can be set as Markdown text (with GitHub flavour). To set custom message please create a welcome.md file and include your Markdown text there. When deploying please set the WELCOME environment variable pointing to your file. For example, in Heroku it will be WELCOME=welcome.md. The example repository with welcome message is here. The example demo showing a Data Science Portfolio is here.

If you don't set the welcome message a simple Welcome! will be displayed. We belive that setting welcome message will give you a great opportunity for customization.

Installation

You can install Mercury directly from PyPi repository with pip command:

pip install mljar-mercury

Installation from GitHub:

pip install -q -U git+https://github.com/mljar/mercury.git@master

Running locally

To run Mercury locally just run:

mercury runserver --runworker

The above command will run server and worker. It will serve Mercury website at http://127.0.0.1:8000. It won't display any notebooks because we didn't add any. Please stop the Mercury server (and worker) for a moment with (Ctrl+C).

Execute the following command to add a notebook to Mercury database:

mercury add <path_to_notebook>

Please start the Mercury server to see your apps (created from notebooks).

mercury runserver --runworker

Notebook development with automatic refresh

The Mercury watch command is perfect when you create a new notebook and want to see what it will look like as a web app with live changes.

Please run the following command:

mercury watch <path_to_your_notebook>

You can now open the web browser at http://127.0.0.1:8000 and find your notebook. When you change something in the notebook code, markdown, or YAML configuration and save the notebook, then it will be automatically refreshed in the web browser. You can track your changes without manual refreshing of the web app.

Mercury commands

Add

Please use add command to add a notebook to the Mercury. It needs a notebook paath as an argument.

Example:

mercury add notebook.ipynb

Delete

Please use delete command to remove notebook from the Mercury. It needs a notebook path as an argument.

Example:

mercury delete notebook.ipynb

List

Please use list command to display all notebooks in the Mercury.

Example:

mercury list

Running in production

Running in production is easy. We provide several tutorials on how it can be done.

• Deploy to Heroku using free dyno
• Deploy to AWS EC2 using t2.micro
• Deploy to Digital Ocean (comming soon)
• Deploy to GCP (comming soon)
• Deploy to Azure (comming soon)

Running with docker-compose

The docker-compose must be run from the Mercury main directory.

Please copy .env.example file and name it .env file. Please point the NOTEBOOKS_PATH to the directory with your notebooks. All notebooks from that path will be added to the Mercury before the server start. If the requirements.txt file is available in NOTEBOOKS_PATH all packages from there will be installed.

Please remember to change the DJANGO_SUPERUSER_USERNAME and DJANGO_SUPERUSER_PASSWORD.

To generate new SECRET_KEY (recommended), you can use:

python -c 'from django.core.management.utils import get_random_secret_key; \
            print(get_random_secret_key())'

Please leave SERVE_STATIC=False because in the docker-compose configuration static files are served with nginx.

The docker-compose will automatically read environment variables from .env file. To start the Mercury, please run:

docker-compose up --build

To run in detached mode (you can close the terminal) please run:

docker-compose up --build -d

To stop the containers:

docker-compose down

Mercury development

The Mercury project consists of three elements:

• Frontend is written in TypeScript with React+Redux
• Server is written in Python with Django
• Worker is written in Python with Celery

Each element needs a separate terminal during development.

Frontend

The user interface code is in the frontend directory. Run all commands from there. Install dependencies:

yarn install

Run frontend:

yarn start

The frontend is served at http://localhost:3000.

Server

The server code is in the mercury directory. Run all commands from there. Please set the virtual environment first:

virtualenv menv
source menv/bin/activate
pip install -r requirements.txt

Apply migrations:

python manage.py migrate

Run the server in development mode (DEBUG=True):

python manage.py runserver

The server is running at http://127.0.0.1:8000.

Worker

The worker code is in the mercury directory (in the apps/notebooks/tasks.py and apps/tasks/tasks.py files). Please activate first the virtual environment (it is using the same virtual environment as a server):

source menv/bin/activate

Run the worker:

celery -A server worker --loglevel=info -P gevent --concurrency 1 -E

Mercury Pro

Looking for dedicated support, a commercial-friendly license, and more features? The Mercury Pro is for you. Please see the details at our website.