📦 Variables
What is a variable?
A named box that stores information. Give it a label, put a value inside!
# Create (STORE)
name = "Alex" # Text
age = 8 # Number
ready = True # Boolean
# Change
score = 0
score = score + 10
# Print (SHOW)
print("Score:", score)
VAR FLOW
VAR → STORE → CHANGE → PRINT
3 Data Types
📝 Text: "Hello" (in quotes)
🔢 Number: 42 (no quotes)
✅ Boolean: True / False
⚠️ Common Mistakes
player name = "x"player_name = "x"
score = "100"score = 100
print scoreprint(score)
ready = trueready = True
🔁 Loops
FOR loop — set number of times
# Repeat 5 times (0,1,2,3,4)
for i in range(5):
print("Hello!")
# Count 1 to 10
for i in range(1, 11):
print(i)
# Use the variable
for i in range(1, 6):
print("Star", i)
WHILE loop — while condition is true
# Count down from 5
count = 5
while count > 0:
print(count)
count = count - 1
FOR vs WHILE — when to use?
🔵 FOR: Know exactly how many times
🟢 WHILE: Don't know how many times
⚠️ Infinite Loop — DANGER!
If the condition never becomes False, the loop runs forever! Always make sure something changes inside the loop.
range() quick guide
range(5) → 0,1,2,3,4
range(1,6) → 1,2,3,4,5
range(0,10,2) → 0,2,4,6,8
🏜️ Conditionals
if score >= 80:
print("You passed! 🌟")
else:
print("Try again! 💪")
IF-ELIF-ELSE (multiple choices)
if score >= 90:
print("Grade: A")
elif score >= 80:
print("Grade: B")
elif score >= 70:
print("Grade: C")
else:
print("Grade: F")
Comparison Operators
> greater than < less than
>= greater or equal <= less or equal
== equal to != not equal to
Boolean Operators
ANDBoth must be True
ORAt least one must be True
NOTFlips True↔False
| A | B | A AND B | A OR B | NOT A |
|---|
| T | T | T | T | F |
| T | F | F | T | F |
| F | T | F | T | T |
| F | F | F | F | T |
🏙️ Functions
# Define (create)
def greet():
print("Hello! 🚀")
# Call (use)
greet()
greet() # Use again!
def greet(name):
print("Hello,", name)
greet("Alex")
greet("Nova")
def add(a, b):
result = a + b
return result
answer = add(5, 3)
print(answer) # 8
Function Path
CALL → RUN → RETURN
Define first, then call!
Parts of a Function
🏷️ Name: What you call it (greet)
📦 Parameter: Input (name)
📋 Body: What it does (indented)
↩️ Return: What it sends back
📋 Sequences & Algorithms
Sequence
Steps in a specific order. Order matters — changing it changes the result!
Algorithm
A precise, step-by-step plan. Exact enough for a robot to follow without asking questions!
Flowchart Symbols
⬭ Oval: Start / End
▭ Rectangle: Action / Step
◇ Diamond: Decision (Yes/No)
→ Arrow: Flow direction
Bot Commands
MOVE — go forward 1 step
TURN_LEFT — rotate 90° left
TURN_RIGHT — rotate 90° right
COLLECT — pick up item
Sequence vs Algorithm
📋 Sequence: "Make a sandwich"
🤖 Algorithm: "Get 2 slices of bread. Spread 5g butter on each slice. Add 2 slices of cheese..."