CS21.3 -- Introduction to Comp Sci
Fall 2010

Schedule | Lab Sessions | Study Sessions | Succeeding | Grading | Quiz Policy | Lab Policy


Class Information

Room: Science Center 240
Class: Tuesday, Thursday 9:55–11:10am
Professor: Charlie Garrod
Office: Science Center 255
Phone: 6071
Office hours: Wednesdays 2 - 3:30, or you can stop by whenever my door is open.

Welcome to CS21. This course will introduce fundamental ideas in computer science and teach 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 CS 35.

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 CS 33 or CS 35.

Required Textbook

Goals for the course

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

Student Support

Student Support Coordinator: Betsy Horner (Office: Science Center 257, Phone: 6062)

CS21 Ninjas (student mentors): Frank Chien, Ashley Oudenne

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
Sunday 7-10pm Sci Center 240
Wednesday 7-9pm Sci Center 240

You are invited -- and encouraged -- to participate in these study sessions to prepare for quizzes, to discuss programming concepts, and to get friendly assistance in working on homework 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. You are not required to attend the lab sessions, but you should take advantage of them to get assistance with your lab assignments. Any CS21 student is welcome to attend any session, and you may attend multiple sessions if you'd like.

Day Time Professor Location
Fridays 2:00-3:30 Knerr Science Center 238
Mondays 2:30-4:00 Meeden Science Center 240
Mondays 3:30-5:00 Garrod 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 local-staff@cs.swarthmore.edu 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

Academic accommodations are available for students with disabilities who are registered with Student Disability Services in the Dean's office. Students in need of disability accommodations should schedule an appointment with me early in the semester to discuss accommodations for this course that have been approved by the Dean's office. All requests must come through an accommodation letter from the Dean's office. To receive an accommodation for a course activity, your meeting with me must be at least one week prior to the activity.

Contact Tracey Rush at the Dean's office and follow these steps for obtaining accommodations.


Grades will be weighted as follows:
40%Lab assignments
5%Class Participation
25%Final Exam

Quiz policy

Quizzes will be given at the beginning of class on the days posted in the Announcements section of 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 typically be assigned on the Schedule in the middle of the week and will be due before midnight the following Tuesday 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 only be accepted if you contact the professor at least a day before the deadline with a legitimate reason for needing extra time, such as an illness or needing to leave campus.

Even if you do not fully complete an assignment, you should submit what you have done to receive partial credit.

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:

Academic Integrity

Academic honesty is required in all work you submit to be graded. With the exception of your lab partner on lab assignments, 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 that for an intentional first offense, failure in the course is normally 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 College Bulletin (2008-2009, Section 7.1.2)

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


1 Aug 31   Introduction to Python and Unix
Zelle chapters 1-2
Sep 02  
2 Sep 07 Quiz 1 study guide Numbers and Strings
Zelle chapters 3-4
Sep 09 Quiz 1
Drop/Add ends (Sep 10)
3 Sep 14   Booleans
Zelle chapter 7 and pg. 247
Sep 16  
4 Sep 21 Quiz 2 study guide Graphics, Objects
Zelle chapter 5
Notes on the Graphics Library
Sep 23 Quiz 2
5 Sep 28   Functions, Objects
Zelle chapter 6
Sep 30  
6 Oct 05 Quiz 3 study guide while Loops, More Functions
Zelle chapter 8
Oct 07 Quiz 3

Oct 12

Fall Break

Oct 14

7 Oct 19   Top Down Design, File I/O
Zelle chapter 9, section 4.6
Oct 21  
8 Oct 26   Dictionaries
Zelle section 11.6
Oct 28  
9 Nov 02 Quiz 4 study guide Searching, Analysis of Algorithms
Zelle section 13.1
Nov 04 Quiz 4
Last day to declare CR/NC or W (Nov 05)
10 Nov 09   Sorting, Analysis of Algorithms
Zelle sections 13.2-13.3
Nov 11  
11 Nov 16 Quiz 5 study guide Recursion
Zelle sections 13.1-13.3
Nov 18 Quiz 5
12 Nov 23   Defining New Classes
Zelle chapter 10

Nov 25

Thanksgiving Break

13 Nov 30   Linked lists
Dec 02  
14 Dec 07   Wrap-up None

Dec 17

Final Exam 7-10pm