Welcome to cs21. This course will introduce fundamental ideas in computer science while also teaching you how to write computer programs. You will study algorithms for solving problems and learn how to implement solutions in the Python programming language. 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 how to 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 either cs31 or cs35.
There is no required textbook for this course. There are, however, required readings! See the Schedule for each week's reading assignment. We will primarily be using the online book How to think like a computer scientist: Learning with Python by Elkner, Downey and Meyers.
Here are a few other useful online python resources:
This course features weekly lab assignments which are the largest component of your course grade. Lab attendance is required by all students, unless you have already completed and submitted the lab assignment for the week. You must attend the lab session for which you are enrolled:
|Weekly Lab Sessions|
|Lab A: Tues. 1:05—2:35pm||Knerr||Science Center 256|
|Lab B: Tues. 2:45—4:15pm||Knerr||Science Center 256|
|Lab C: Thur. 1:05—2:35pm||Ngai||Science Center 240|
|Lab D: Thur. 2:45—4:15pm||Meeden||Science Center 240|
Lab assignments will typically be posted on the web by Sunday afternoon and will be due before midnight on Saturdays. 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, and a history of previous submission will be saved. You are encouraged to submit your work regularly.
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.
Quizzes will be given at the beginning of class on the days posted in the Announcements section of the Schedule. Please look at these dates carefully and contact me in advance if you cannot be in class for a quiz.
Academic honesty is required in all of your work. Under no circumstances may you hand in work done with (or by) someone else under your own name. 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, but is not limited to, obtaining solutions from students who previously took the course or code that can be found online. You may not share solutions after the due date of the assignment. However, 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.
All code you submit must be your own with the following permissible exceptions: code distributed in class, code found in the assigned readings for the course, 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.
Failure to abide by these rules constitutes academic dishonesty and will lead to a hearing of the College Judiciary Committee. According to the Faculty Handbook: "Because plagiarism is considered to be so serious a transgression, it is the opinion of the faculty that for the first offense, failure in the course and, as appropriate, suspension for a semester or deprivation of the degree in that year is suitable; for a second offense, the penalty should normally be expulsion." Be aware that we will be routinely running plagiarism detection software on the lab solutions of students from all sections of cs21.
Please contact me if you have any questions about what is permissible in this course.
Lauri Courtenay is the CS Department's Academic Support Coordinator. She will be working closely with our student mentors, also known as Ninjas, to help you learn how to program and think like a computer scientist. The Ninjas for this semester are: Isabel (Izzi) Baskin, Alexander Simms, Afua (Dee) Ahima, Allison Ryder, Daniel Redelmeier, and Justin Cosentino.
You are invited, and encouraged, to participate in Ninja evening 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 snacks will be provided at the sessions. The sessions are held:
|Weekly Evening Ninja Sessions|
|Mondays||7—9pm||Sci Center 256|
|Thursdays||7—10pm||Sci Center 256|
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 firstname.lastname@example.org 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, 240, and 256.
If you believe that you need accommodations for a disability, please contact Leslie Hempling in the Office of Student Disability Services (Parrish 113) or email email@example.com to arrange an appointment to discuss your needs. As appropriate, she will issue students with documented disabilities a formal Accommodations Letter. Since accommodations require early planning and are not retroactive, please contact her as soon as possible. For details about the accommodations process visit Student Disability Services.
|WEEK||DAY||ANNOUNCEMENTS||TOPIC & READING||LABS|
|Introduction to Python and Unix ||Lab 0: Unix and editing|
|Writing simple programs||Lab 1: First programs|
|if-else; Booleans ||Lab 2: Numbers and strings|
|First functions, While loops||Lab 3: Conditionals, if|
|Graphics; Using objects||Lab 4: while loops|
|Functions||Lab 5: Using graphics|
|Top-down design; File input/output||Lab 6: Defining functions|
|Searching, Analysis of algorithms ||Lab 7: Top-down design|
|Sorting, Analysis of algorithms||Lab 7 continued|
Last day to declare CR/NC or W
|Recursion ||Lab 8: Using search/sort|
|Defining new classes ||Lab 9: Using recursion|
|More on classes||None|
|Linked lists ||Lab 10: Defining objects|
|Wrap up||Lab 11: Using linked lists|
Final Exam 7-10pm in SCI 101