CS 101: Introduction to Programming with Python

Course Syllabus

A first course in computer science. No prior programming experience is assumed; if you have written code before, this course will deepen and formalize what you already know.

Table of Contents

• Course Information
• Course Description
• Prerequisites
• Learning Outcomes
• Open Textbooks
• Tools and Environment
• Lessons
  • Lesson 1: Programs, Variables, and Expressions
  • Lesson 2: Decisions and Repetition
  • Lesson 3: Functions and Structured Problem Solving
• Course Schedule (14 weeks)
• Assessment
• Course Policies
• Resources

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Course Information

Course number	CS 101
Title	Introduction to Programming with Python
Credits	3
Level	Undergraduate, first year
Format	Lecture + supervised lab; three lessons per module
Offered	Fall and Spring

This is an open course. Every textbook on the reading list is available free online, and the teaching materials below are released under a Creative Commons license so you may keep, remix, and reuse them.

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Course Description

CS 101 introduces the science of computation through the Python programming language. Students learn to think algorithmically and to express those ideas as correct, readable programs. The course begins with the mechanics of the language, moves through fundamental control structures and functions, and finishes by composing small programs that read data, make decisions, and automate real work.

Python is chosen for three reasons: it reads close to English, it is used seriously in industry and research, and it is free. Everything you need to follow this course can be installed on your own machine in a few minutes, and several of the assigned books can be completed entirely in a browser.

Prerequisites

• High-school algebra.
• Comfort using a computer: opening applications, creating files, and using a browser. No programming or terminal experience required.

Learning Outcomes

By the end of this course, a successful student will be able to:

1. Explain what a program is and trace how the Python interpreter executes simple statements.
2. Write programs that store and manipulate data using the core types (numbers, strings, booleans, lists, dictionaries).
3. Use conditions and loops to make a program that branches and repeats.
4. Define and call functions, and explain the difference between a function and a procedure.
5. Read and write text files, and work with data structures to solve small, realistic problems.
6. Debug programs by reading error messages and testing incrementally.

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Open Textbooks

A dozen free, high-quality books follow, ordered from the most beginner friendly to the most challenging. All are readable online in a browser; most also offer PDF and EPUB editions. Pick one as your primary text and use the others for reference or a different voice.

Part A: Foundations (start here)

1. Think Python, 3rd Edition (Interactive) by Allen B. Downey https://allendowney.github.io/ThinkPython/ The course's primary text. Short chapters, lots of small examples, and a running series of exercises. The interactive edition runs directly in the browser, so you can edit and execute code as you read.

2. Python for Everybody (PY4E) by Dr. Charles Severance https://www.py4e.com/book A data-oriented introduction aimed at readers with no programming background. Every chapter pairs with a video lecture; the site includes autograded exercises and a practice quiz per chapter.

3. How to Think Like a Computer Scientist: Interactive Edition (Runestone) https://runestone.academy/ns/books/published/thinkcspy/index.html A community-maintained, fully interactive version of the classic text, with embedded code blocks, coloring, and auto-graded exercises. Excellent if you prefer to practice as you read.

4. A Byte of Python by Swaroop C. H. https://python.swaroopch.com/ A short, friendly primer intended for total beginners. Good first read if a big textbook feels intimidating; it covers the essential language features in a weekend's reading.

5. Think Python, 2nd Edition by Allen B. Downey (Green Tea Press) https://greenteapress.com/wp/think-python-2e/ The earlier edition of the primary text, available free under a Creative Commons license. Use it if you prefer a more traditional print-style layout or the older chapter numbering referenced in some archives.

Part B: Applications and practice

6. Automate the Boring Stuff with Python, 3rd Edition by Al Sweigart https://automatetheboringstuff.com/ Practical programming for total beginners. Where most texts stop at language features, this one shows you how to do real work: rename files, scrape web pages, fill out forms, and work with spreadsheets. The free online edition is the canonical version.

7. Invent Your Own Computer Games with Python, 4th Edition by Al Sweigart https://inventwithpython.com/invent4thed/ Learn by building games. Each chapter presents the complete source code for a small game (Guess the Number, Hangman, Tic Tac Toe) and teaches the underlying concepts from the example. A great way to stay motivated.

8. Dive Into Python 3 by Mark Pilgrim https://diveintopython3.net/ A book for people who already know how to program in another language and want to pick up Python 3 quickly. Strong on strings, comprehensions, generators, and working with files and web services.

Part C: Reference and depth

9. The Coder's Apprentice by Pieter Spronck https://spronck.net/pythonbook A thorough course book written for readers with no prior programming knowledge. Numerous exercises per chapter, end-of-chapter summaries, and downloadable code listings. Free as a PDF.

10. How to Think Like a Computer Scientist (Open Book Project edition) https://www.openbookproject.net/thinkcs/python/english2e/ The original openly licensed edition, stable and complete, with a simple chapter-per-page layout. Useful as a second, quietly-archived reference.

11. Python Programming (Wikibooks) https://en.wikibooks.org/wiki/Python_Programming A community-written reference that covers the language and standard library in depth. Not a linear tutorial, but the best place to look up a specific topic quickly.

12. The Python Tutorial (official) https://docs.python.org/3/tutorial/ The language's own tutorial, maintained by the Python Software Foundation. Authoritative and concise; the final authority for any syntax question.

How to choose

• Reading nothing but one Part A book is enough to pass.
• Add one Part B book if you want projects that do something visible.
• Keep a Part C book open while you code; it answers the "wait, is there a built-in for this?" questions.

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Tools and Environment

• Python 3.12 or newer. Install from https://python.org/. This course uses Python 3; Python 2 is not supported.
• A text editor or IDE of your choice. Any editor works; VS Code, PyCharm Community, and Thonny are common choices.
• If you cannot install software, use an online environment such as the Runestone textbook's built-in interpreter or thinkpython's Colab notebooks.
• A terminal. Several readings assume you can run python3 script.py from a command line. Getting comfortable with the terminal is part of the course's outcome.

Running your first program

Create a file named hello.py containing:

print("Hello, world!")

Then, from a terminal in the same directory:

python3 hello.py

If you see Hello, world! printed, your environment is ready.

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Lessons

The course is organized into three lessons, each building on the last. Work through them in order. Each lesson is self-contained: a set of objectives, assigned reading, the core concepts with worked examples, and a short assignment.

Lesson 1: Programs, Variables, and Expressions

Objectives After this lesson you can: distinguish between a value, an expression, and a statement; use Python's interactive shell; store data in variables; and write arithmetic and string expressions.

Reading

• Think Python 3e, Chapters 1 and 2.
• A Byte of Python, "First Steps" and "Operators and Expressions".
• The Python Tutorial, sections 1 through 3.

Key ideas

• A value is a piece of data: 5, "hello", True.
• A variable is a name that refers to a value: x = 5.
• An expression is a combination of values, variables, and operators that evaluates to a value: x + 3.
• A statement is an instruction the interpreter runs: print(x).
• Types matter: 7 + 3 is 10, but "7" + "3" is "73".

Worked example

name = "Ada"
age = 36
print(name + " is " + str(age) + " years old.")
print(age * 12, "months")

Practice In the shell, predict the value of each of these before running them, then check yourself:

5 // 2
5 % 2
2 ** 10
"ab" * 3
0.1 + 0.2

Assignment 1 Write a program that converts a temperature in Celsius to Fahrenheit using F = C * 9 / 5 + 32. Read the Celsius value from a variable you set at the top of the file, and print both the Celsius and the Fahrenheit values to the nearest tenth.

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Lesson 2: Decisions and Repetition

Objectives After this lesson you can: make a program take different paths with if/elif/else; repeat work with for and while loops; use range to loop a known number of times; and write a boolean expression.

Reading

• Think Python 3e, Chapters 3 and 4.
• Python for Everybody, Chapters 3 and 4.
• The Python Tutorial, section 4.

Key ideas

• A boolean expression is True or False: age >= 18.
• Conditional execution picks a path based on a boolean:

  if score >= 90:
      print("A")
  elif score >= 80:
      print("B")
  else:
      print("C")

• A loop repeats a block. Use for when you know how many times; use while when you repeat until a condition changes.

  for n in range(5):
      print(n)
  
  n = 0
  while n < 5:
      print(n)
      n += 1

Worked example

total = 0
for n in range(1, 101):
    total += n
print("The sum of 1..100 is", total)

Practice Write a loop that prints every even number from 2 to 20. Then write a while loop that counts down from 5 to 1 and prints "Go!" at the end.

Assignment 2 Write a program that asks how many integers it should read (use input()), reads that many integers, and then prints the largest and the smallest. Handle the case where the user enters zero numbers without an error.

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Lesson 3: Functions and Structured Problem Solving

Objectives After this lesson you can: define a function with def; pass arguments and return values; explain the difference between a function that returns a value and one that produces a side effect; and break a problem into small, testable functions.

Reading

• Think Python 3e, Chapter 5.
• The Coder's Apprentice, "Functions" and "Simple Functions".
• Python for Everybody, Chapter 4.

Key ideas

• A function is a named block of code you can call:

  def greet(name):
      return "Hello, " + name

• A returned value can be used in an expression; a side effect (like printing) happens but is not a value.
• Functions let you write a program once and reuse it, and they are the smallest unit worth unit testing.
• Scope matters: variables defined inside a function are local to it.

Worked example

def is_odd(n):
    return n % 2 != 0

def classify(n):
    if is_odd(n):
        return "odd"
    return "even"

for n in range(1, 6):
    print(n, classify(n))

Practice Write a function average(a, b) that returns the average of two numbers. Then write average_list(nums) that takes a list and returns its average. Both should be usable from a main() that prints a couple of test cases.

Assignment 3 Write a small program with at least three functions that computes a simple grade report. Read a list of scores (each 0 to 100), compute the average, assign a letter grade, and print a one-line summary per student. Keep the input reading, the grade computation, and the printing in separate functions so each can be tested on its own.

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Course Schedule (14 weeks)

Week	Topic	Lesson
1	What is a program; installing Python	Lesson 1
2	Values, variables, expressions, types	Lesson 1
3	Input, output, and the interactive shell	Lesson 1
4	Strings and string methods	Lesson 1
5	Booleans and comparisons	Lesson 2
6	Conditional execution (if/elif/else)	Lesson 2
7	for loops and range	Lesson 2
8	while loops and loop patterns	Lesson 2
9	Defining functions, arguments, return values	Lesson 3
10	Scope and local variables	Lesson 3
11	Lists and recursion (introduction)	Lesson 3
12	Files and reading data	Lesson 3
13	Putting it together: a graded project	Lesson 3
14	Review and final project presentations	All

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Assessment

Component	Weight
Three lessons (assignments 1, 2, 3)	45%
Weekly short quizzes	15%
Midterm	20%
Final project	20%

Grading scale: A 93+, A- 90, B+ 87, B 83, B- 80, C+ 77, C 73, C- 70, D 60, F below 60.

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Course Policies

Late work

Assignments are due at the start of the week in which they appear. Late work is accepted for one week with a 10% penalty per day, unless an extension was arranged in advance for a documented reason.

Collaboration

You are encouraged to discuss concepts with classmates. However, the code you submit must be your own. Copying another student's work, or submitting the output of an automated tool without understanding it, is a violation of the academic integrity policy and will be treated as such.

Academic integrity

All work submitted for a grade must be your own. Sharing or receiving answer files is not permitted. If you use material from outside this course, cite it. When in doubt, ask.

Accessibility

This course is designed to be open and usable by everyone. All required reading is free and available online. If you need an accommodation, contact the instructor early in the term so it can be arranged.

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Resources

• Official Python documentation: https://docs.python.org/3/
• Python tutorial: https://docs.python.org/3/tutorial/
• Python on this course's machine: everything runs through python3; the same code works on Windows, macOS, and Linux.
• Community help: the #learnpython channels are generally friendly to beginners. Describe what you expected, what happened, and include the exact error message.

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This syllabus is offered as open course material. You are free to copy, adapt, and redistribute it for non-commercial teaching use under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 license. The books listed above retain their own licenses as noted by their authors.