Skip to content

Getting Started

All notebooks run in Google Colab, a free service from Google that runs Python in your web browser. All you need is a Google account.

Opening a notebook

  1. Go to any lesson page and click the Open in Colab button.
  2. The notebook opens in a new browser tab.
  3. If Colab asks you to sign in, use your Google account.

Running the code

A notebook is made of cells. There are two kinds:

  • Text cells explain what is happening. Read these.
  • Code cells have a grey background and a play button on the left.

To run a code cell, click the play button, or click inside the cell and press Shift + Enter. Run the cells in order, from top to bottom. Each cell builds on the ones above it.

Run everything at once

The menu option Runtime > Run all runs every cell in order. This is handy if you only want to see the results.

The first cell installs packages

Each notebook starts with a cell like this:

!pip install osmnx leafmap

This installs the extra tools the notebook needs. It takes about a minute, and you can ignore the long text it prints. If Colab shows a warning about restarting the session, click Restart session, then carry on from the next cell.

Warnings in red

You may see messages in red or pink boxes that say Warning. These are usually harmless notes from the software. An actual problem says Error and stops the cell from running.

Saving your work

Colab does not save your changes to the original notebook. To keep your own version:

  • File > Save a copy in Drive saves it to your Google Drive.

When something goes wrong

  • A cell fails with NameError. You probably skipped a cell. Run the cells above it first.
  • Downloads are slow or time out. The data servers can be busy. Wait a minute and run the cell again.
  • OpenStreetMap downloads fail with 502, 504 or Read timed out. Lessons 1 to 5 and 10 download OSM data from the public Overpass server, which is sometimes overloaded. Wait a few minutes and try again, or switch to a mirror server by running this line after the imports: ox.settings.overpass_url = "https://overpass.kumi.systems/api"
  • Everything is stuck. Use Runtime > Restart session, then Runtime > Run all.

Changing the study area

Every notebook uses Bengaluru, but you can switch to your own city. Look for the settings cell near the top:

CITY = "Bengaluru, Karnataka, India"

Change the name or the coordinates to your own city and run the notebook again. Some ward data only exists for Bengaluru, and the notebooks point out where that is the case.