CHAPTER 6 — STRINGS - Printable Version

CHAPTER 6 — STRINGS - Printable Version

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CHAPTER 6 — STRINGS - Leejohnston - 11-15-2025

Chapter 6 — Strings
Understanding and controlling text in Python

A string is simply text inside quotation marks.

Strings are used for:
• names
• messages
• sentences
• user input
• filenames
• any text your program displays

Python gives you powerful tools to create and manipulate strings.

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6.1 Creating Strings

Strings always go inside quotes:

Code:
name = "Johno"

colour = "blue"

message = "Welcome to Python!"

You can use:
• double quotes " "
• or single quotes ' '

Both are fine:

Code:
word1 = "hello"

word2 = 'hello'

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6.2 Printing Strings

Simple:

Code:
print("Hello there!")

Or using variables:

Code:
name = "Mia"

print(name)

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6.3 Combining Strings (Concatenation)

Use + to join strings:

Code:
first = "Hello"

second = "world"

print(first + " " + second)

Output:

Code:
Hello world

Remember:
You can only add strings to strings.

This fails:

Code:
age = 16

print("Age: " + age)  # ERROR

Fix using str():

Code:
age = 16

print("Age: " + str(age))  # Works

---

6.4 Repeating Strings

Python lets you multiply a string:

Code:
print("ha" * 3)

Output:

Code:
hahaha

Useful for patterns, dividers, or simple banners.

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6.5 Escape Characters (Special Symbols)

Sometimes you need quotation marks *inside* your string.

Python uses backslashes to escape them:

Code:
print("He said \"Hello!\"")

Common escape codes:
• \n — new line
• \t — tab
• \" — quote
• \\ — backslash

Example:

Code:
print("Line 1\nLine 2")

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6.6 String Length

Use len() to measure the number of characters:

Code:
word = "Python"

print(len(word))

Output:

Code:
6

Counting includes:
• spaces
• letters
• numbers
• punctuation

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6.7 Indexing — Getting Individual Characters

Each character has a position:

Code:
text = "hello"

print(text[0])  # h

print(text[1])  # e

Important:
• Python starts counting at 0
• Last character = index -1

Example:

Code:
print(text[-1])  # o

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6.8 Slicing — Getting Parts of a String

Format:

Code:
string[start:end]

Example:

Code:
word = "Python"

print(word[0:3])  # Pyt

print(word[2:6])  # thon

Start is included.
End is NOT included.

Shortcut examples:

Code:
print(word[:3])  # from start to position 3

print(word[3:])  # from position 3 to end

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6.9 Changing Case

Python has built-in string functions:

Code:
message = "hello world"

print(message.upper())  # HELLO WORLD

print(message.lower())  # hello world

print(message.title())  # Hello World

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6.10 Removing Spaces

Stripping spaces from ends:

Code:
text = "  hello  "

print(text.strip())  # "hello"

Other options:
• .lstrip() — left only
• .rstrip() — right only

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6.11 Finding Substrings

Check if part of a string exists:

Code:
sentence = "Python is powerful"

print("power" in sentence)      # True

print("weak" in sentence)      # False

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6.12 Replacing Parts of a String

Code:
text = "I like apples"

new_text = text.replace("apples", "oranges")

print(new_text)

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6.13 Exercise — Sentence Tools

Create a file called string_tools.py.

Ask the user for a sentence.
Then print:

1. The length of the sentence
2. The first character
3. The last character
4. The sentence in uppercase
5. The sentence reversed

(Hint: reversed string =

Code:
text[::-1]

)

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6.14 Small Challenge

Ask the user for:
• their first name
• their last name

Then output:

Code:
"Initials: F.L."

(Hint: first character of each name)

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6.15 Chapter Summary

• Strings store text
• Use + to combine strings
• Use * to repeat strings
• Escape characters allow quotes, new lines, etc.
• len() counts characters
• Indexing gets single letters
• Slicing gets parts of a string
• .upper(), .lower(), .title() change case
• .strip() removes spaces
• .replace() replaces text

Next:
Chapter 7 — Numbers & Maths in Python

Now your programs begin to calculate real values.

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Written and Compiled by Lee Johnston — Founder of The Lumin Archive