String and Integer (deeper)
🟦🐍 Deeper Dive: What’s Really Happening with str and int in Python?
🧠 Big Idea
Computers don’t know what “text” or “numbers” are the way we do. They only understand binary — 1s and 0s.
But programming languages like Python help us label and use things like "hello" and 42 in a human way.
🔢 What’s an int?
An int is a whole number.
age = 10
🧠 Inside the computer, 10 is stored as binary: 00001010
Python treats this as a number it can:
- Add, subtract, multiply
- Compare (
>,<) - Use in loops or math
🔤 What’s a str?
A str is text, like:
name = "Alex"
Each letter in "Alex" is stored as a character code:
"A"= 65"l"= 108"e"= 101"x"= 120
🧠 These are stored using something called ASCII or Unicode.
So "Alex" becomes:
[65, 108, 101, 120] → 01000001 01101100 01100101 01111000
The computer sees a list of character codes, not letters!
❌ Why Can’t You Add a str and an int?
name = "Alex"
age = 10
print(name + " is " + age + " years old.")
🔴 This fails because Python sees:
"Alex" + " is " + [a number??] + " years old."
You’re mixing text with a number. Python says: “I don’t know how to glue these together.”
✅ You must convert the number into text with str(age) or use an f-string:
print(f"{name} is {age} years old.")
🧠 Type Checking
Use type() to see what kind of thing you're using:
print(type("Alex")) # <class 'str'>
print(type(10)) # <class 'int'>
🧪 Did You Know?
"5"and5look similar but behave very differently."5" + "3"="53"(text joined together)5 + 3=8(math!)
💬 What Does This All Mean?
You’re not just writing text and numbers — you’re giving instructions to a machine that sees everything as patterns of bits.
Understanding this helps you:
- Fix errors faster
- Explain your code to others
- Start thinking like a real computer scientist
📎 Optional Extension
Try this challenge:
score = "7"
print(score + 3) # What happens?
print(int(score) + 3) # What changes?
🛠️ Practical Technique Card
To look at how to actually use str and int in projects please check out:
📹 Video Link
