CS Colloquium: “How Python Tutor Became a Long-Lasting and Widely Used Academic Software Project,” Philip Guo
September 4, 2026 11 a.m.–12 p.m.
Location
Galileo Hall, Pryne
240 Platt Blvd.
Claremont, CA 91711
Contact
Morgan McArdle
mmcardle@g.hmc.edu
909.607.0299
Details
“One Developer, Two Decades and Thirty Million Users Later: How Python Tutor Became a Long-Lasting and Widely Used Academic Software Project”
Since 2009, Philip Guo has been developing Python Tutor, a tool that lets users write code in a web browser and see what happens step-by-step as the computer runs it. The tool visualizes variables, objects, pointers, data structures and stack frames. These visuals help students to debug their homework, teachers to explain concepts and programmers to prepare for job interviews. Despite its name, this tool visualizes code written in Python, Java, C, C++ and JavaScript, which are five of the most popular languages used in both teaching and industry.
Throughout the past two decades, over 30 million students and teachers from over 180 countries have used Python Tutor to visualize over 500 million pieces of code. Guo will reflect upon the design decisions (and non-decisions) he made to turn an off-the-cuff prototype into one of the most widely used pieces of academic software. He will cover three eras of Python Tutor development:
- Act I - Inception, the unique conditions that birthed this idea as a grad student side project.
- Act II - Acceleration, sustaining a decade's worth of user growth as he began his career as a professor.
- Act III - Disruption, when Generative AI both threatens the health of this project and may also be what revitalizes it.
About the Speaker
Philip Guo is a professor of cognitive science at UC San Diego. His research spans human-computer interaction, computing education and human-centered AI for education. He studies how people learn computer programming and data science, and he builds tools to help people better understand code and data. For instance, his Python Tutor educational tool has been used by 30 million students and teachers from over 180 countries throughout the past two decades. Python Tutor received a UIST Best Paper award and the ACM SIGCSE Test of Time award for long-term impact. His other lines of research have received 10-year long-term impact awards from VL/HCC and ISSTA, along with Best Paper awards at CHI, UIST, SIGCSE, VL/HCC, ICSE and ISSTA.
This event is for: faculty, staff, students
faculty, staff, studentsCommunity Connections events provide opportunities for HMC faculty, students and staff to cultivate community, foster open conversations and share important information as together we live out our mission and shape the future of the College.
Calendars
Kickstart your career journey by joining us each week for the OCS career and professional development series! From expert panels to hands-on workshops and presentations, each session dives into a new topic designed to help you build skills and confidence for your future.
This faculty panel will explore “dangerous questions” from a variety of disciplines to understand and respond to challenges facing American universities. The discussion will address the erosion of knowledge and expertise, as well as political forces that may attempt to limit intellectual inquiry and creativity.
Ambereen Dadabhoy, asssociate professor of literature, “What Would Shakespeare Say?”
Anup Gampa, assistant professor of psychology, “Invasive Species: Blaming Dysregulated Plant Neighbors Is a ‘Settler Move’ to Innocence”
Rachel Mayeri, artist and professor of media studies, “What Can Art Do During a Fascist Takeover?”
David K. Seitz, associate professor of cultural geography, “Geography Against Immediacy”
Paul Steinberg, professor of political science and environmental policy, “Creative Politics as a Strategic Response to Authoritarianism”
David Wilson, assistant professor of music, “Sounding (Anti-)Authoritarian: A Few Vignettes”
The K-12 through college CS pipeline is full of barriers and those barriers prevent broader participation in the field. I’ll describe some of my research to try to identify or remove some of those barriers. I hope you will learn a bit more about CS education research and how you can advocate for policies and practices that can broaden participation in CS!
“We don’t want to live in a society in turmoil. In the U.S., 93 percent of people want to reduce divisiveness, and 86 percent believe it’s possible to disagree in a healthy way. Yet with increasing political and social fragmentation, many of us don’t know how to move past our differences. Civil rights scholar john a. powell presents an actionable path through ‘bridging’ that helps us communicate, coexist and imagine a new story for our shared future where we all belong.” (description courtesy of Othering and Belonging Institute)
The Office of Civic and Community Engagement (OCCE) will be hosting a guilt-free book club this fall semester on john a. powell’s book The Power of Bridging: How to Build a World Where We All Belong. Our first gathering is on Friday, Oct. 3.
This learning community is for everyone, from those who are already experienced in community engagement to those who are curious about learning more about this high-impact educational practice. Faculty participants will discuss readings, meet with outside speakers, share ideas, and think collaboratively about implementing community engagement into the 5C students’ experience.
Welcome to HMC’s Community Conversations for the fall 2025.
HMC Community Conversations* use conversation guides with a structured format to help people with different viewpoints and experiences build understanding. There will be 3–5 other people in a table group. It is not a debate, and the goal is not to change one another’s opinions. There are Conversation Agreements like “Listen and Be Curious” and “Show Respect and Suspend Judgement” that create the framework for diving into the questions. The questions are designed to draw out our personal experiences rather than opinions around the topic.
The overall purpose is to learn more about the experiences others have around the topic and build a sense of community.
Community Conversations will take place on Tuesdays from 11 a.m. to noon in Shanahan 1480; and each gathering will be on a separate topic. Gatherings will be in person only.
Kickstart your career journey by joining us each week for the OCS career and professional development series! From expert panels to hands-on workshops and presentations, each session dives into a new topic designed to help you build skills and confidence for your future.
Learn about HMC’s approved study abroad programs and how to study abroad your junior year.
The Great ShakeOut is an opportunity for our community to practice what to do during an earthquake (drop, cover, and hold on). In the event of a real earthquake, a notification will be sent via Mudd Alert containing important information and instructions.
In most situations, if you feel shaking or receive an earthquake alert, you should immediately:
Drop where you are, onto your hands and knees. This position protects you from being knocked down and reduces your chances of being hit by falling or flying objects.
Cover your head and neck with one arm and hand. If a sturdy table or desk is nearby, crawl underneath for shelter. If no shelter is nearby, crawl next to an interior wall. Stay on your knees; bend over to protect vital organs.
Hold on until the shaking stops. If you’re under shelter, hold on to it with one hand and be ready to move with your shelter if it shifts. If you are not under shelter, cover your head and neck with both arms and hands.
For the purpose of this exercise, we encourage community members to practice these steps for one minute upon receiving the Mudd Alert notification. Thank you for your time and participation in this important emergency preparedness exercise.
“We don’t want to live in a society in turmoil. In the US, 93 percent of people want to reduce divisiveness, and 86 percent believe it’s possible to disagree in a healthy way. Yet with increasing political and social fragmentation, many of us don’t know how to move past our differences. Civil rights scholar john a. powell presents an actionable path through “bridging” that helps us communicate, coexist, and imagine a new story for our shared future where we all belong.” (taken from Othering and Belonging Institute)
The Office of Civic & Community Engagement (OCCE) will be hosting a guilt-free book club this fall semester on john a. powell’s book The Power of Bridging: How to Build a World Where We All Belong. Our first gathering is on Friday, October 3rd.
This learning community is for everyone, from those who are already experienced in community engagement to those who are curious about learning more about this high-impact educational practice. Faculty participants will discuss readings, meet with outside speakers, share ideas, and think collaboratively about implementing community engagement into the 5C students’ experience.
Welcome to HMC’s Community Conversations for the fall 2025.
HMC Community Conversations* use conversation guides with a structured format to help people with different viewpoints and experiences build understanding. There will be 3–5 other people in a table group. It is not a debate, and the goal is not to change one another’s opinions. There are Conversation Agreements like “Listen and Be Curious” and “Show Respect and Suspend Judgement” that create the framework for diving into the questions. The questions are designed to draw out our personal experiences rather than opinions around the topic.
The overall purpose is to learn more about the experiences others have around the topic and build a sense of community.
Community Conversations will take place on Tuesdays from 11 a.m. to noon in Shanahan 1480; and each gathering will be on a separate topic. Gatherings will be in person only.
Kickstart your career journey by joining us each week for the OCS career and professional development series! From expert panels to hands-on workshops and presentations, each session dives into a new topic designed to help you build skills and confidence for your future.
Professor Paul Steinberg teaches the popular course Public Speaking for Science and Citizenship. In this workshop, he’ll share insights on public speaking and lead a fun and easy Audience-ology™ exercise.
Steinberg is professor of political science and environmental policy in the Department of Humanities, Social Sciences, and the Arts, where he holds the Malcolm Lewis Chair in Sustainability and Society. The author of three books and recipient of the International Studies Association’s Deborah Gerner Award for Innovation Teaching, Steinberg runs the firm PS Public Speaking.
The Cabinet is hosting informal coffee breaks in fall 2025 for students, faculty, and staff. These coffee breaks will be attended by most of the Cabinet team and will provide an opportunity for the community to share ideas, express concerns, and highlight successes.
All are welcome to stop by as schedules allow.
“We don’t want to live in a society in turmoil. In the US, 93 percent of people want to reduce divisiveness, and 86 percent believe it’s possible to disagree in a healthy way. Yet with increasing political and social fragmentation, many of us don’t know how to move past our differences. Civil rights scholar john a. powell presents an actionable path through “bridging” that helps us communicate, coexist, and imagine a new story for our shared future where we all belong.” (taken from Othering and Belonging Institute)
The Office of Civic & Community Engagement (OCCE) will be hosting a guilt-free book club this fall semester on john a. powell’s book The Power of Bridging: How to Build a World Where We All Belong. Our first gathering is on Friday, October 3rd.
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