CS21: Intro to Computer Science (Knerr)

Info | Study Sessions | Schedule | Grading
Succeeding | Style | Accommodations | Integrity | Links
Introduction to Computer Science using P Y T H O N -- Fall 2009


  • The FINAL EXAM is Dec 17, 7-10pm, in SciCntr 101
  • Review Sessions: Sunday 7-9pm (Ninjas), Tuesday 4:30-6:30pm (Danner)


Welcome to CS21! 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 CS35. If you have no prior computer science or programming experience, this course is designed for you.

Goals for the Course

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

Class info (Fall 2009)

Room: Science Center 240
Time: MWF 11:30–12:20am
Text: There is no required text for this course. However, if you would like a reference, here are two we recommend (the weekly schedule lists related material from both):

Instructional staff

Professor: Jeff Knerr
Office: Science Center 238A
Phone: (610) 690-5758
Office hours: by appointment

Student Support: Betsy Horner
Office: Science Center 257
Phone: 957-6062

Student Mentors:Maria Kelly, Sarah Chasins, Frank Chien, John Dinh, Kwame Osei
Other Sections: Andrew Danner (MWF 10:30–11:20am) | Tia Newhall (TR 11:20–12:35)

Study sessions

Several student mentors 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 7:00–9:00pm Sci Center 240
Wednesday 7:00–9:00pm 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 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 is often 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 main CS labs to help CS21 students with their lab assignments. You are not required to attend any of these sessions, but you should take advantage of them to get assistance with your lab assignments. Any CS21 student is welcome to attend any session.
Time Professor Location
Monday 2:30–4:00pm Danner Sci Center 240
Monday 3:30–5:00pm Newhall Sci Center 240
Friday 1:00–2:00pm * Knerr Sci Center 256 (the robot lab)

* if there's a campus collection, the Friday lab will be 2-3pm


1 Aug 31 Getting Started Introduction to Python and Unix
Ch. 1-2 (Z), Ch. 1-Ch. 2 (D)
In class: week 1 MWF
Assn: lab 0
Assn: lab 1
Sep 02  
Sep 04  
Sep 07   Numbers and Strings
Ch. 3-4 (Z), Ch. 2 (D)
In class: week 2 MWF
Assn: lab 2
Sep 09  
Sep 11 Drop/Add Ends; (Q1)
Sep 14   Booleans
Ch. 7 and p. 247 (Z), Ch. 5.1-5.7, Ch. 7 (D)
In class: week 3 MWF
Assn: lab 3
Sep 16  
Sep 18  
Sep 21   Graphics, objects
Zelle Chapter 5
The Graphics Library
Tia's Using the Graphics Library
In class: week 4 MWF
Assn: lab 4
Sep 23  
Sep 25 Practice Quiz (pdf)
Sep 28   Functions, objects
Ch. 6 (Z), Ch. 3, Ch. 6 (D)
READ Section 6.2 in the Downey book!!
In class: week 5 MWF
Assn: lab 5
Sep 30  
Oct 02  
Oct 05   while Loops, more functions
Ch. 8, 9 (Z), Ch. 7 (D)
strings and lists as objects
using the random library
In class: week 6 MWF
Assn: lab 6
Oct 07  
Oct 09 Practice Quiz (pdf)

Oct 12

Fall Break

Oct 14

Oct 16

Oct 19   Top Down Design, File I/O
Ch. 9, 4.6 (Z), Ch. 14 (D)
In class: week 7 MWF
Assn: lab 7
Oct 21  
Oct 23  
Oct 26   Searching, Analysis of Algorithms
Ch. 13.1 (Z), Ch. 9 (D)
In class: week 8 MWF
Oct 28  
Oct 30 Practice Quiz 4
Nov 02   Recursion, Sorting
Ch. 13.2-13.3 (Z), Ch. 5.8-5.10, 9 (D)
In class: week 9 MWF
Assn: lab 8
Nov 04  
Nov 06 CR/NC/W Deadline
Nov 09   More Searching, Sorting and Recursion
Ch. 13.1-13.3 (Z)
In class: week 10 MWF
Assn: lab 9
Nov 11  
Nov 13 Practice Quiz
Nov 16   Defining new classes
Ch. 10 (Z), Ch. 15-17 (D)
In class: week 11 MWF
Assn: lab 10
Nov 18  
Nov 20  
Nov 23   Object Oriented Design
Ch. 12 (Z), Ch. 15-17 (D)
In class: week 12 MW
Assn: lab 11 start
Nov 25  

Nov 27

Thanksgiving Break

Nov 30   Linked lists
In class: week 13 MW
Assn: lab 11
Dec 02  
Dec 04 Quiz 6 (practice)
Dec 07   Wrapup
In class: TBA week 14
Dec 09      

Dec 11

Final Exams Start

Dec 17

CS21 Final Exam 7-10pm


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

Lab and Homework policy

Programming assignments will typically be assigned in class at the beginning or 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 not be accepted except in extreme situations and only if you contact me before the deadline. Even if you do not fully complete an assignment, you may submit what you have done to receive partial credit.

How to Succeed in CS21

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 example of good style.

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.

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. You may not examine or use work done by others to complete your own work. 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 the student mentors and your partner on group assignments, you may not work with others on your assignments.

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 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.

"It is the opinion of the faculty 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." - Student Handbook (2009-2010, pg18 Section I.B.3.b.i)

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.

Vi Quick Reference
Python style guide From Prof. Tia Newhall
Using Unix Improved
Basic Unix Commands
Python Documentation
How To Think Like a Computer Scientist: Python for Software Design
Zelle Textbook site
Dive Into Python
(A Semi-Official) Python FAQ Zone
NodeBox (for Mac OS X)