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Welcome to CS515: Intro to Computer Science!
Week 1: Basic
Welcome!
Part 1: The Basics of Numbers and Variables
Mystery Operator
Variables
Variable Declarations
Variable Declarations, Part 2
Operator Precedence
Viral Twitter Math Problem
Temperature Conversion Mixup
Part 2: Using Functions
Working on Your Abs
Call Me, Maybe
Nesting Function Calls
Smaller of the Two
Smaller of the Three
Greatest Magnitude
Part 3: A Datatype for Text
Comma Chameleon
Longest String
Escaping
Escaping Practice
Part 4: Mixing Type is (Sometimes) an Error
Which Throws an Error?
Sum of Ints
Part 5: Input and Output
Copypasta
Pleased to Meet you!
Stretch Goals
Defining Our Own Functions
Cubes
Triangle Time
I Am Very Excited!!!!!!!
Floating Point Numbers, Redux
Which Are Floats?
Which Are Integers?
There and Back Again: Converting Between Integers and Floats
Converting with int to float
Adding, Subtracting, Multiplying and Dividing with Floating-Point Numbers
Does It float?
It Dosen’t Float!
Division: / versus //
Does It Float Again?
Conversions and Promotions
Introduction to Booleans
Expressions Yielding True
Expressions Yielding False
Boolean Expressions Using Variables
Writing Boolean Expressions
Functions Returning Booleans
Booleans Summary
Conditioning on Booleans with If Statements
Validating Values
More Conditions
Room Assignments
Default Conditions
Passing Grades
Characterizing Numbers
Computing the Lengths of Strings
Name Length
Indexing
Safe Indexing
Slicing
Slicing (without Dicing)
String Comparison
Using `in` and `not in` Operators
Comparing Strings
String Membership
Passing Arguments to Functions
What’s good about functions?
Parameters vs. arguments
Parameter names vs. argument names
Shared names and shadowing
Guten Tag!
The call stack
What’s On Your Stack?
Scope: local vs. global
Local variables only exist during function calls
Characteristics of local and global variables
Reading Code
Updating global variables from inside a function
You can count on me!
Week 2: Data structures and loops
Checking In about Datatypes
Defining Lists
List Indexing and Lookup
Last in Line
Summing the Ends
Slicing Lists
Slicing Lists: Your Turn!
Operations on Lists
Testing Membership in Lists
List Membership
List Length
Strings and Lists in Python
Splitting and Joining
Filtering and Mapping
Absolute Values
Map of the Territory
Mapping and Summing
What is a reference?
What is an object?
References, Objects, and Aliasing
How to find out if references point to the same object?
Fruit Salad (Part 1)
Fruit Salad (Part 2)
Fruit Salad (Part 3)
Absolute Values
A method to our madness
Counting needles in a haystack
Excuse me, this is a library
Dots and dashes
List methods
List methods!
Now backwards is talking
For loops
Home on the range
For/range output
Factorial
Using for loops with lists
How many times does it run?
Finding something in a list
Hip to be square
Counting evens and odds
While loops
Tracing a while loop
Tracing a while loop, redux
multiply_3
Searching with while loops
abs_more_than_10
User input validation
Input length validation
Infinite while loops
Break statements
Take a break to think about break
is_positive_or_multiple_of_7
Break statements in for loops
Understanding for loop with breaks
Find Python!
Continue statements
print_numbers
Randomness
Fair Die Roll
What and why are dictionaries?
Creating dictionaries
Burgeoning lexicographers
Looking things up in a dictionary
Lookup is looking up
Working with dictionaries
Adding and deleting keys
Adding/deleting practice
Constraints on dictionary keys
More lookup practice
Tuples as dictionary keys
Dictionary and tuple practice
insert_pair
How big is the dictionary?
len on dictionaries
Using methods for lookup
Get it?
Methods for adding and deleting items
News update
Looping over dictionaries
What should we loop over?
combined_cases
Finding the mode in a list of numbers
find_mode
count_total_words
Storing lists in dictionaries
print_emails
Storing dictionaries in dictionaries
Dictionaries within dictionaries
Data processing
Accessing and updating data
Getting data out
Actually processing the data
lookup_state
Data with nested dictionaries
Organizing Data
Working with nested data
Lab grades
Processing nested data
is_above_85
Sets
Uniqueness
Week 3: Exceptions, recursion, and nested loops
Errors that end your program early
Syntax errors
Name/variable binding errors
Type errors
Errors from partial operations
Interruptions from the user and the environment
What kind of error?
Try/except statements
Exceptional control flow
Breakfast
Stack traces
Catching only certain exceptions
Hardened square-root program
Raising exceptions
Exceptional control flow, redux
Catching errors early with assert
Testing types with isinstance
isinstance
Surprise: integers and floats are unrelated
Surprise: bools are numbers!
Recursion: functions that call themselves
Identifying the parts
Sum and length
Visualizing recursive call stacks
Concatenating nested strings
Recursion into iteration (and vice versa)
What can’t a single for loop do?
Nested for loops
Simulating nested for loops
Iterate through lists using inner for-loops
More simulation
Predicting COVID cases
Doing your times tables
[OPTIONAL] Prime numbers
Lists of lists
Making a 2D list
Indexing nested lists
Nested lists
Nested for loops and 2D lists
increment_2D
What is an image?
Images and 2D lists
Pixel numbering
Pixels, Color and RGB
Color quiz
Tuples
create_pixel
Tuples and 2D lists
red_square
Recap
Accessing rows of images
Getting a row
Accessing columns of images
Getting a column
Nested for loops to access images
Getting a column
Modifying pixels of an image
Modifying pixels using for loops
More for loops
Blacking out checkers
Apply a red filter to an image
red_filter_pixel
Using for loops
Red filter
Working in just a region of an image
Red shifted region
Customizing red_filter
Thinking about custom_red_filter
custom_blue_filter
Handling edge cases
Bad inputs
custom_blue_filter, revisited
Flipping images left-to-right
Flipping cats
Flipping with nested for loops
More of a flop than a flip
List swap
We’re all tired at this point in the semester
Defining a function for flip
red_filter, in place
Returning an image
Understanding objects and references
Creating a copy of an image
Copying and flipping
Copies and references
Overwriting references
Overwriting references
red_filter, copying
Recursion Workbook
Recursion Practice
List sum
List minimum
Linear search
Stutter
Even-indexed elements
Odd-indexed elements
Map
Zip
Alternate
Everywhere
Summing nested dictionaries
Tries
Week 4: Objects and classes
What is an object?
Surprise: we’ve been using objects!
Which are method calls?
Creating objects: constructors
Using constructors
Defining objects: classes
Constructors
Working with fields
Sum
Defining methods
Adder
Private fields with __
SmallCounter
Printing objects out
Sum with
__repr__
Objects and classes: recap
Finding your way around
Explaining what you’re about
Doctest: putting your tests in your documentation
Testing mean
Inheritance
Inheritance
Classy testing
Testing median
Week 5: Regular expressions
Turning strings into structured things
Running example: DNA and amino acid motifs
DNA and amino encoding
Translating DNA to amino acids
Translating DNA to amino acids
Motifs
Finding motifs by hand
Regular expressions: a better way
Characters and character classes
Matching practice
The re module
re.findall practice
Special characters, escape characters, and raw strings
Escaping practice
Choice a/k/a parallel composition; groups
Choice practice
Repetition
US phone numbers
Unbounded repetition
Using re.search, re.match, and re.fullmatch
Practice with Match objects
ISO 8601 dates
Substitutions and backreference
A word of caution
Week 6: Algorithms
What is an algorithm?
Shuffling: stating the problem
The Fisher-Yates shuffle
Bottom-up Fisher-Yates
Shuffling wrong
Empirically testing shuffle implementations
Searching
Linear search
Sortedness
Testing for sortedness
Binary search
Understanding search algorithms
Sorting algorithms
Insertion sort: the “natural” sort
Insertion sort with loops
Selection sort
Descending selection sort
Quicksort
Choosing the pivot element
Quicksort with median pivot
Merge sort
Merging sorted lists
Week 7: Python Details
Real world Python
Defining your own modules
Defining modules
Nested modules
__name__ == “__main__”
Get you a module that can do both
Variable arity with *args
Variable arity minimum and maximum
Named arguments with defaults with keyword arguments and **kw
Sort by key
Anonymous functions with lambda
Anonymous function practice
Iterables
The Collatz conjecture
Making generators with the yield keyword
Practice with generators
Comprehensions
Practice with comprehensions
Arithmetic overloading
Practice with overloading
Unpacking patterns
Enumerations of fixed values
Type annotations
Decorators change behavior
Document field names and types with data classes
Further reading
Repository
Show source
Suggest edit
Open issue
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Guten Tag!
Guten Tag!
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