Lecture 2: Strings and Lists

Autumn 2026

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Sli.do

#cse163

Questions?

Icebreaker

Watch any good movies or shows recently?

CSE 163

CSE 163: Strings and Lists

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Announcements

• Section Check in 1 is due tonight (Friday) on Gradescope at 11:59pm
• Complete this Intro Survey, due Tuesday, October 6th at 11:59pm
• Will replace a missed lesson review.
• Homework 1 released today, due Thursday, October 8 at 11:59pm
• Make sure you have access to all the course materials
• Ed, JupyterHub, Gradescope, Canvas
• If you just enrolled: wait about 24 hours for the rosters to update
• If you are having trouble running Python files or accessing JupyterHub, please come to office hours or post on Ed.

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CSE 163: Strings and Lists

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Today’s Roadmap

1. Reminder: Course Website
2. Functions
3. Strings and Lists
4. Methods vs. Built-in Functions
5. Practice Problems!

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CSE 163: Strings and Lists

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Reminder: Course Website

• All course information and resources can be found on the course website.
• Course schedule and announcements
• Assignments, lecture recordings, section materials
• Office Hours
• Course resources (e.g. JupyterHub, Ed, Gradescope, etc.)
• …and more
• Canvas will only be used to display grades, everything else will be on the course website. Please do not contact course staff via Canvas.

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cs.uw.edu/163

CSE 163: Strings and Lists

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Anatomy of a Function

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def function_name(parameter, ...):

#Function code

return value

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def keyword

Function name

Optional

parameters

Function code

colon

Indentation

Return statement

CSE 163: Strings and Lists

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Strings and Lists

• Strings
• Text data that has indices for characters
• Has functions to transform (and return new) strings!
• String slicing

• Lists
• Indexed-sequence (like strings) but can hold values of more data types.
• The Java equivalent is an ArrayList

• Documentation
• Doc-string (““ documentation ””)

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CSE 163: Strings and Lists

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Strings and Lists!

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JupyterHub

CSE 163: Strings and Lists

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Type/Structure Methods vs. Built-in Functions

• Data types/structures have methods unique to them.

• Built-in Python functions are not unique to a specific data types/structure

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s = "oN yOuR lEfT!"

print(s.upper()) #.upper() for strings

print(s.lower()) #.lower() for strings

s = "oN yOuR lEfT!"

c = ["blue", "green", "red", "yellow"]

print(len(s)) # len works for strings!

print(len(c)) # len works for lists!

CSE 163: Strings and Lists

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Type/Structure Methods vs. Built-in Functions

• Data types/structures have methods unique to them.

• Built-in Python functions are not unique to a specific data types/structure

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s.method(optional,...))

function(s)

Can you think of any other built-in functions?

CSE 163: Strings and Lists

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s = 'on your left!'

# Length

len(s) # 13

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# Indexing

s[1] # 'n'

s[len(s) - 1] # '!'

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# Looping

for i in range(len(s)):

print(s[i])

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for c in s:

print(c)

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l = ['blue', 'red', 'green']

# Length

len(l) # 3

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# Indexing

l[1] # 'red'

l[len(l) - 1] # 'green'

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# Looping

for i in range(len(l)):

print(l[i])

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for word in l:

print(word)

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CSE 163: Strings and Lists

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Practice Problems!

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JupyterHub

CSE 163: Strings and Lists

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