Python Chapter 2

📘 Variables

• A variable stores data in memory.
• Example:name = "Alice" age = 15
• Rules for variables:
  1. Must start with a letter or underscore (_)
  2. Cannot start with a number
  3. Case-sensitive (Name ≠ name)
  4. No spaces or special symbols
  5. Don’t use Python keywords

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🔢 Data Types

Type	Example	Description
int	10	Whole numbers
float	3.14	Decimal numbers
str	“Hello”	Text or characters
bool	True / False	Logical values
list	[1, 2, 3]	Collection of items
tuple	(1, 2, 3)	Ordered and unchangeable items
dict	{“name”:”Ali”, “age”:15}	Key-value pairs

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💬 Input and Output

• Input: input("Enter your name: ")
• Output: print("Hello")
• Input is always a string, use int() or float() to convert.

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➕ Operators

🔹 Arithmetic Operators

+, -, *, /, %, **, //

🔹 Comparison Operators

==, !=, >, <, >=, <=

🔹 Logical Operators

and, or, not

🔹 Assignment Operators

=, +=, -=, *=, /=

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🔣 Type Conversion

Change data type using:

int(), float(), str()