This syllabus is a living document; please be aware that many elements on this page will change throughout the semester, including the course schedule. It is the student's responsibility to review this page periodically for updates.

Class Info

Section 4: MWF 10:30–11:20am, Science Center 240
Professor: Richard Wicentowski
email: richardw @
Office: Science Center 251
Phone: x5643
Office hours: 1:00-4:00 Tuesday and by appointment

This course will introduce fundamental ideas in computer science while also teaching you how to write computer programs. We will study algorithms for solving problems and implement solutions in the Python programming language. Python is an interpreted language that is known for its ease of use. We also introduce object-oriented programming and data structures. A deeper coverage of these topics will be presented in CS35.

This course is appropriate for all students who want to learn how to write computer programs and think like computer scientists. It is the usual first course for computer science majors and minors. Students with advanced placement credit or extensive programming experience should place out of this course and instead begin with CS31 or CS35.

Required Textbook:

Goals for the course:

By the end of the course, we hope that you will have developed the following skills:


This is a tentative schedule; it may change as we go.
1Jan 21   Introduction to Python and Unix
Zelle Ch 1,2
Lab 0: linux & xemacs
Jan 23  
Jan 25  
2Jan 28   Numbers and Strings
Ch 3 (all), Ch 4 just 4.1,4.2,4.3
Lab 1: first programs
Jan 30  
Feb 01 Drop/Add ends (Feb 1)
3Feb 04 Quiz 1 Study Guide if/else, Booleans
Sect. 7.1,7.2,7.3 and 8.4.1 (pg. 246-7)
Lab 2: strings
Feb 06 Quiz 1
Feb 08  
4Feb 11   Graphics, Objects
Ch 5 (skip 5.5, 5.6)
Notes on the Graphics Library
Lab 3: if/elif/else
Feb 13  
Feb 15  
5Feb 18 Quiz 2 Study Guide Functions, Objects
Ch 6 (skip 6.3)
Lab 4: graphics
Feb 20 Quiz 2
Feb 22  
6Feb 25   while Loops, More Functions
Sect 8.1,8.2,8.3
Function worksheet on
Lab 5: snail racing
Feb 27  
Mar 01  
7Mar 04 Quiz 3 Study Guide Top-Down Design, File I/O
Sect 9.1,9.2,9.3, Sect 4.6 (files)
Lab 6: slot machines
Mar 06 Quiz 3
Mar 08  

Mar 11

Spring Break

Mar 13

Mar 15

8Mar 18   More Top-Down Design
Sect 9.1,9.2,9.3
Lab 7: text twist *DESIGN*
Mar 20  
Mar 22  
9Mar 25 Quiz 4 Study Guide Searching, Analysis of Algorithms
Sect 13.1
Mar 27 Quiz 4
Mar 29 Last day to declare CR/NC or W
10Apr 01   Sorting, Analysis of Algorithms
Sect 13.3
Lab 8: Authorship Detection
Apr 03  
Apr 05  
11Apr 08 Quiz 5 Study Guide Recursion
Sect 13.2
Lab 9: Sorting stock data
Apr 10 Quiz 5
Apr 12  
12Apr 15   Defining new classes
Sect 10.1,10.3.1,10.4
Lab 10: Recursion
Apr 17  
Apr 19  
13Apr 22 Quiz 6 Study Guide Linked lists
Lab 11: Swindle
Apr 24 Quiz 6
Apr 26  
14Apr 29   Advanced Topics, Wrap-up Lab 12: Linked lists
May 01  
May 03 Final exam Study Guide

May 11

Final exam 2pm-5pm in SciCtr 101

Student Support

Student Support Coordinator: Frances Ruiz (Office: Sci Ctr 257; phone: x6062)

CS21 Ninjas: Samantha Goldstein, Mike Lumetta, Cynthia Ma, Sid Reddy, Leah Foster, Chris Magnano, Jocelyn Adams, Kwame Koram

Samantha and Mike will be specifically assigned to our class, but all the ninjas will be able to help you with class concepts, quizzes and labs.

Study sessions

The CS Ninjas will assist me in class and run study sessions in the main CS lab (Science Center 240) on the following evenings:

Day Time Location
Mondays 7-9pm Sci Center 240
Wednesdays 7-10pm Sci Center 240

You are encouraged to participate in these study sessions to prepare for quizzes, to discuss class concepts, and to get friendly assistance in working on lab assignments. Our CS mentoring team is dedicated to helping students, who have no prior knowledge of computer science, learn to program in Python while keeping their senses of humor intact. As an added bonus, free food will be provided at the sessions.

Lab Sessions

The CS lab is open 24 hours a day, 7 days a week for you to use for CS21 lab assignments. In addition, the CS21 professors will be in the CS labs at the times listed below to help CS21 students with lab assignments. The professors expect you to attend at least one lab section per week unless you have already completed your lab assignment. You are free to attend whichever lab section you choose to attend or to attend multiple sections.

Time Professor Location
1:00-2:30 Mondays Knerr Science Center 240
2:30-4:00 Mondays Knerr Science Center 240
1:30-3:00 Tuesdays Griffin Science Center 240
3:00-4:30 Tuesdays Griffin Science Center 240

Accessing the CS labs after hours

You can use your ID to gain access to the computer labs at nights and on the weekends. Just wave your ID over the microprox reader next to the lab doors. When the green light goes on, just push on the door handle to get in (the door knob will not turn). If the green light doesn't go on, then we need to enter your microprox number into the system. email if you have problems with this. If the building is locked, you can use your ID to enter the door between Martin and Cornell library. For this class, your ID will give you access to the labs in rooms 238 and 240.

How to Succeed in CS 21

Academic Accommodations

If you believe that you need accommodations for a disability, please contact Leslie Hempling in the Office of Student Disability Services, located in Parrish 130, or e-mail lhempli1 to set up an appointment to discuss your needs and the process for requesting accommodations. Leslie Hempling is responsible for reviewing and approving disability-related accommodation requests and, as appropriate, she will issue students with documented disabilities an Accommodation Authorization Letter. Since accommodations may require early planning and are not retroactive, please contact her as soon as possible. For details about the Student Disabilities Service and the accomodations process, visit the Office of Student Disability Services.

You are also welcome to contact me privately to discuss your academic needs. However, all disability-related accommodations must be arranged through Leslie Hempling in the Office Of Student Disability Services.

To receive an accommodation for a course activity, you must have an Accomodation Authorization letter from Leslie Hempling and you need to meet with me to work out the details of your accommodation at least one week prior to the activity.


Grades will be weighted as follows:
25%Final Exam
5%Class Participation

Quiz policy

Quizzes will be given at the beginning of class on the days posted in the Schedule. Please look over these dates carefully and contact the professor in advance if you cannot be in class for a quiz.

If you are not present at the start of class on the day of a quiz, but make it to class before the end, then you may take the quiz. Otherwise you will receive a zero for that quiz.

Lab policy

Lab assignments will be posted on the Schedule on Friday and will be due before midnight the following Friday night. You are strongly encouraged to start early and to attend the study sessions for extra practice.

You will submit you assignments electronically using the handin21 program. You may submit your assignment multiple times, but each submission overwrites the previous one and only the final submission will be graded.

Late assignments will not be accepted except in extreme situations and only if you contact me at least a day before the deadline with a legitimate reason for needing extra time, such as an illness.

Even if you do not fully complete an assignment, you should submit what you have done to receive partial credit. Unless otherwise stated, labs are to be completed individually. Please carefully read the statement on academic integrity for more information.

Programming Style

Programming is not a dry mechanical process, but a form of art. Well written code has an aesthetic appeal while poor form can make other programmers and instructors cringe. Programming assignments will be graded based on style and correctness. Good programming practices usually include many of the following principles:

Also, look over the Python Code Style Guide for more details and some examples of good code style.

Academic Integrity

Academic honesty is required in all work you submit to be graded. You may not submit work done with (or by) someone else, or examine or use work done by others to complete your own work. Your code should never be shared with anyone; you may not examine or use code belonging to someone else, nor may you let anyone else look at or make a copy of your code. This includes sharing solutions after the due date of the assignment.

All code you submit must be your own with the following permissible exceptions: code distributed in class, code found in the course text book, and code worked on with an assigned partner. In these cases, you should always include detailed comments that indicates on which parts of the assignment you received help, and what your sources were.

Discussing ideas and approaches to problems with others on a general level is fine (in fact, we encourage you to discuss general strategies with each other), but you should never read anyone else's code or let anyone else read your code. You may discuss assignment specifications and requirements with others in the class to be sure you understand the problem. In addition, you are allowed to work with others to help learn the course material. However, with the exception of your lab partner, you may not work with others on your assignments in any capacity.

"It is the opinion of the faculty as a whole that for an intentional first offense failure in the course normally is appropriate. Suspension for a semester or deprivation of the degree in that year may also be appropriate when warranted by the seriousness of the offense." - Swarthmore Student Handbook

Please see me if there are any questions about what is permissible.

Links that are related to the course may be posted here. If you have suggestions for links, let me know.

  • Python style guide
  • Using Unix Improved
  • Basic Unix Commands
  • Prof. Newhall's Unix Documentation
  • Python Documentation (Note: we are using v2.7)
  • How To Think Like a Computer Scientist: Python for Software Design
  • Zelle Textbook site
  • Dive Into Python
  • (A Semi-Official) Python FAQ Zone
  • Python tutorial
  • Vi Quick Reference