🔹 1. What Are Variables?
A variable is like a container that stores data in memory.
You can give it a name and assign a value.
Example:
x = 10
name = "Sakshi"
pi = 3.14
print(x, name, pi)
Rules for naming variables:
• Must start with a letter or underscore (_)
• Can contain letters, numbers, and underscores
• Case-sensitive (name ≠ Name)
• Cannot use Python keywords (like for, if, while)
🔹 2. Python Data Types
Python automatically detects the type of data (dynamic typing).
| Type | Example | Description |
|---|---|---|
| int | 10 | Whole numbers |
| float | 3.14 | Decimal numbers |
| str | "Hello" | Text data |
| bool | True, False | Logical values |
| list | [1, 2, 3] | Ordered, changeable collection |
| tuple | (1, 2, 3) | Ordered, unchangeable collection |
| set | {1, 2, 3} | Unordered, unique elements |
| dict | {"name": "Sakshi", "age": 20} | Key-value pairs |
Example:
a = 10
b = 3.14
c = "Python"
d = True
e = [1, 2, 3]
f = (4, 5, 6)
g = {7, 8, 9}
h = {"name": "Sakshi", "age": 19}
🔹 3. Type Checking and Conversion
Check variable type:
x = 42
print(type(x))
Convert between types:
x = 10
y = float(x)
z = str(x)
print(y, z)
🔹 4. Getting User Input
Example:
name = input("Enter your name: ")
age = int(input("Enter your age: "))
print("Hello", name, "you are", age, "years old.")
🔹 5. Multiple Assignments
Example:
x, y, z = 10, 20, 30
print(x, y, z)
a = b = c = 0
🧠 Quick Practice Tasks
Simple Calculator – Take two numbers and print their sum, difference, product, and division.
User Info Display – Ask for name, age, and city; display in formatted output.
Data Type Identifier – Ask for user input and print its data type using type().
