Digest

This episode of Talk Python features Wilhelm Klopp, the creator of Kolo, a visual studio code extension for Django that helps developers understand their code better. Kolo visualizes the flow of code, showing how functions are called and how data is passed through them. It also provides a playground in the browser where users can edit code and see how the visualization changes. Kolo can also be used to generate integration tests, which are more valuable than unit tests for ensuring that code doesn't break by accident. Kolo is not entirely open source, but Klopp is considering open sourcing parts of it in the future. He also discusses the possibility of a Colo Cloud, which would allow users to share traces and collaborate on code. The episode concludes with a call to action for listeners to check out Kolo.app and email Klopp if they are interested in increasing their test coverage.

Outlines

00:00:00

Introduction

This Chapter introduces the topic of Kolo, a visual studio code extension for Django that helps developers understand their code better. The host, Michael Kennedy, welcomes Wilhelm Klopp, the creator of Kolo, to the show.

00:02:13

Wilhelm Klopp's Background

This Chapter delves into Wilhelm Klopp's background, highlighting his journey from a management degree to building a successful Slack app called Simple Poll. He shares his experience working at GitHub and how Simple Poll eventually became his full-time job, surpassing his GitHub salary.

00:04:13

The Genesis of Kolo

This Chapter explores the origins of Kolo, explaining how it started as a side project to improve Wilhelm Klopp's own developer experience while building Simple Poll. He emphasizes the initial focus on Django and VS Code due to his personal usage.

00:05:04

The Time Commitment of Side Projects

This Chapter delves into the time commitment required for side projects, particularly in the early stages. Wilhelm Klopp shares his experience dedicating significant hours to Simple Poll, even while working full-time as a software engineer. He discusses the challenges of balancing work, support, and development, and the potential benefits of prioritizing and focusing on the most important aspects of a project.

00:09:42

Simple Poll: A Django-Based Slack App

This Chapter focuses on Simple Poll, a popular Slack app built using Django. Wilhelm Klopp explains the technical aspects of building Slack apps, emphasizing the backend-based approach and the use of JSON payloads for communication. He also discusses the deployment history of Simple Poll, from Heroku to AWS and ECS.

00:12:33

Kolo: Visualizing Code Flow

This Chapter introduces Kolo in detail, highlighting its core functionality of visualizing code flow. Wilhelm Klopp explains the concept of visualizing the mental model of how code functions fit together, comparing it to enabling a debugger at the beginning and end of every function. He emphasizes the focus on hierarchy and understanding code dependencies, rather than just timing.

00:18:28

Kolo Playground and Interactive Visualization

This Chapter showcases the Kolo playground, a web-based version of Kolo that allows users to interact with code and see the visualization change in real-time. Wilhelm Klopp describes the playground's features, including the ability to edit code and see how the visualization changes, and the use of PyDiode and web assembly for running Python in the browser.

00:20:15

Kolo's Test Generation Capabilities

This Chapter explores Kolo's test generation capabilities, which leverage the trace data captured by Kolo to automatically create integration tests. Wilhelm Klopp explains the process of inverting traces to build tests, focusing on the challenges of test data setup and the benefits of integration tests over unit tests.

00:36:07

Future Plans for Kolo

This Chapter discusses Wilhelm Klopp's future plans for Kolo, including expanding support beyond Django to other web frameworks like Flask and Fast API, and exploring the potential of a Colo Cloud for sharing traces and collaborating on code. He also addresses the question of open sourcing Kolo, suggesting that parts of it may become open source in the future.

Keywords

Q&A

• What is Kolo and what does it do?

  Kolo is a visual studio code extension for Django that helps developers understand their code better. It visualizes the flow of code, showing how functions are called and how data is passed through them. It also provides a playground in the browser where users can edit code and see how the visualization changes.

• How does Kolo generate integration tests?

  Kolo uses the trace data it captures to automatically create integration tests. It inverts the traces, turning the actions taken in a request into test steps. This includes setting up test data, making requests, and asserting the results.

• What are the benefits of integration tests over unit tests?

  Integration tests are more valuable than unit tests for ensuring that code doesn't break by accident. They test the interactions between different components of a system, providing a more comprehensive view of how the code works together.

• What are Wilhelm Klopp's future plans for Kolo?

  Klopp plans to expand Kolo's support beyond Django to other web frameworks like Flask and Fast API. He is also exploring the possibility of a Colo Cloud, which would allow users to share traces and collaborate on code. He is considering open sourcing parts of Kolo in the future.

• What is the business model for Kolo?

  Kolo is not entirely open source, and Klopp is working on a sustainable business model for it. He believes that test generation capabilities could be a key feature for a premium or enterprise version of Kolo.

• What is the current state of Kolo's support for other editors besides VS Code?

  Kolo is currently only available for VS Code, but Klopp is working on a web-based version that will be available for all editors. He also mentions that Pie Charm support is a top request and is being considered for the future.

• How does Kolo handle data privacy?

  Kolo is currently a fully local product, meaning that code and trace data never leave the user's system. However, Klopp is exploring the possibility of a Colo Cloud, which would require a different approach to data privacy.

• What is the call to action for listeners interested in Kolo?

  Listeners are encouraged to check out Kolo.app and the playground at play.colo.app. They are also encouraged to email Klopp at w@colo.app if they are interested in increasing their test coverage or collaborating on Kolo.

• What is the significance of Kolo's focus on Django?

  Django is a popular and influential web framework in the Python community. By focusing on Django, Kolo can reach a large and engaged audience of developers who are already familiar with the framework.

• How does Kolo compare to other debugging tools?

  Kolo goes beyond traditional debugging tools by providing a more visual and interactive way to understand code flow. It also captures more detailed information, including the data returned by database queries, which can be helpful for debugging and testing.

Show Notes