Chapter 3: Python Operators

Part 1: Arithmetic Operators

1. + (Addition Operator)

Kya karta hai: Do numbers ya strings ko jodta hai.

Rule: dono values same type ki honi chahiye (int + int, str + str)
# Example 1: Adding two numbers a = 10 b = 5 print(a + b)
15
# Example 2: Adding strings (concatenation) name = "Hello " surname = "World" print(name + surname)
Hello World
# Wrong Example: Mixing types a = 5 b = "hello" print(a + b) # ❌ Error: unsupported operand type(s)

2. - (Subtraction Operator)

Kya karta hai: Ek value ko doosri se ghatata hai (number only).

Rule: strings ya non-numeric types par subtraction allowed nahi hai.
a = 20 b = 7 print(a - b)
13
print("hello" - "h") # ❌ Error: unsupported operand types

3. * (Multiplication Operator)

Kya karta hai: Do numbers ko multiply karta hai ya string ko repeat karta hai.

# Multiplying numbers print(4 * 3)
12
# String repetition print("Hi " * 3)
Hi Hi Hi

4. / (Division Operator)

Kya karta hai: Do numbers ko divide karta hai (result always float).

print(10 / 2)
5.0
print(10 / 0) # ❌ Error: ZeroDivisionError
Rule: 0 se kabhi divide mat karo – program crash karega.

5. % (Modulus Operator)

Kya karta hai: Remainder return karta hai (sheshfal).

print(10 % 3)
1

6. ** (Exponentiation)

Kya karta hai: Power calculate karta hai (x ki power y).

print(2 ** 3) # 2 × 2 × 2
8

7. // (Floor Division)

Kya karta hai: Divide karta hai aur result ka sirf integer part return karta hai (floor value).

print(10 // 3)
3
Note: Useful jab decimal ignore karna ho.
Chapter 3: Assignment Operators - Python

Part 2: Assignment Operators

1. = (Simple Assignment)

Kya karta hai: Variable ko value assign karta hai.

Rule: Variable ko ek value dena.
a = 5 # Assigning value 5 to variable 'a' print(a)
5
# Wrong Example: 5 = a # ❌ Error: SyntaxError (left side must be a variable)

2. += (Add and Assign)

Kya karta hai: Existing value me given number add karke, usi variable ko assign karta hai.

a = 10 a += 5 # a = a + 5 print(a)
15
# Wrong Example: a = 5 a += "hello" # ❌ Error: unsupported operand type(s)

3. -= (Subtract and Assign)

Kya karta hai: Existing value me given number subtract karke, usi variable ko assign karta hai.

a = 10 a -= 3 # a = a - 3 print(a)
7
# Wrong Example: a = 5 a -= "world" # ❌ Error: unsupported operand type(s)

4. *= (Multiply and Assign)

Kya karta hai: Existing value ko given number se multiply karke, usi variable ko assign karta hai.

a = 4 a *= 3 # a = a * 3 print(a)
12
# Wrong Example: a = "hello" a *= 3 # okay, string ko repeat karega print(a)
hellohellohello

5. /= (Divide and Assign)

Kya karta hai: Existing value ko given number se divide karke, usi variable ko assign karta hai.

a = 12 a /= 3 # a = a / 3 print(a)
4.0
# Wrong Example: a = 0 a /= 0 # ❌ Error: ZeroDivisionError

6. %= (Modulus and Assign)

Kya karta hai: Existing value ka modulus leke, usi variable ko assign karta hai.

a = 15 a %= 4 # a = a % 4 print(a)
3

7. **= (Exponentiation and Assign)

Kya karta hai: Existing value ko given number ke power se raise karke, usi variable ko assign karta hai.

a = 2 a **= 3 # a = a ** 3 print(a)
8

8. //= (Floor Division and Assign)

Kya karta hai: Existing value ko floor division karke, usi variable ko assign karta hai.

a = 10 a //= 3 # a = a // 3 print(a)
3
Chapter 3: Comparison Operators - Python

Part 3: Comparison Operators

1. == (Equal to)

Kya karta hai: Check karta hai ki dono values barabar hain ya nahi.

Rule: dono values same honi chahiye, tabhi return True hoga.
a = 5 b = 5 print(a == b) # True
True
a = 5 b = 10 print(a == b) # False
False

2. != (Not Equal to)

Kya karta hai: Check karta hai ki dono values barabar nahi hain.

a = 5 b = 10 print(a != b) # True
True
a = 5 b = 5 print(a != b) # False
False

3. > (Greater than)

Kya karta hai: Check karta hai ki left value greater hai ya nahi.

a = 10 b = 5 print(a > b) # True
True
a = 5 b = 10 print(a > b) # False
False

4. < (Less than)

Kya karta hai: Check karta hai ki left value less hai ya nahi.

a = 3 b = 5 print(a < b) # True
True
a = 10 b = 5 print(a < b) # False
False

5. >= (Greater than or Equal to)

Kya karta hai: Check karta hai ki left value greater ya equal hai ya nahi.

a = 5 b = 5 print(a >= b) # True
True
a = 3 b = 5 print(a >= b) # False
False

6. <= (Less than or Equal to)

Kya karta hai: Check karta hai ki left value less ya equal hai ya nahi.

a = 5 b = 10 print(a <= b) # True
True
a = 10 b = 5 print(a <= b) # False
False
Chapter 3: Logical Operators - Python

Part 4: Logical Operators

1. and

Kya karta hai: Dono conditions True hone par hi result True hota hai.

Rule: Dono conditions ko True hona zaroori hai.
a = 5 b = 10 print(a > 3 and b < 15) # True
True
a = 5 b = 10 print(a > 6 and b < 15) # False
False

2. or

Kya karta hai: Agar kisi ek condition ka result True ho to result True hota hai.

Rule: Agar ek condition True ho, to result True hoga.
a = 5 b = 10 print(a > 6 or b < 15) # True
True
a = 5 b = 10 print(a > 6 or b > 15) # False
False

3. not

Kya karta hai: Condition ko invert karta hai. Agar condition True hai to False return karega, aur agar False hai to True.

Rule: Condition ko reverse ya negate karta hai.
a = 5 print(not a > 10) # True
True
a = 5 print(not a > 3) # False
False
Chapter 3: Bitwise Operators - Python

Part 5: Bitwise Operators

1. & (Bitwise AND)

Kya karta hai: Dono numbers ke corresponding bits ko AND karta hai. Agar dono bits 1 hain, tab result 1 hoga.

Rule: Bits ko AND kiya jata hai. Agar dono bits 1 hain, result 1 hota hai.
# Bitwise AND example a = 5 # 0101 in binary b = 3 # 0011 in binary result = a & b print(result) # 1 (0001 in binary)
1
# Bitwise AND example a = 5 b = 7 result = a & b print(result) # 5 (0101 in binary)
5

2. | (Bitwise OR)

Kya karta hai: Dono numbers ke corresponding bits ko OR karta hai. Agar koi bhi bit 1 ho, result 1 hoga.

Rule: Bits ko OR kiya jata hai. Agar koi bhi bit 1 ho, result 1 hota hai.
# Bitwise OR example a = 5 # 0101 in binary b = 3 # 0011 in binary result = a | b print(result) # 7 (0111 in binary)
7
# Bitwise OR example a = 4 b = 7 result = a | b print(result) # 7 (0111 in binary)
7

3. ^ (Bitwise XOR)

Kya karta hai: Dono numbers ke corresponding bits ko XOR karta hai. Agar dono bits alag hain, tab result 1 hota hai.

Rule: Agar dono bits alag hain, result 1 hota hai.
# Bitwise XOR example a = 5 # 0101 in binary b = 3 # 0011 in binary result = a ^ b print(result) # 6 (0110 in binary)
6
# Bitwise XOR example a = 4 b = 7 result = a ^ b print(result) # 3 (0011 in binary)
3

4. ~ (Bitwise NOT)

Kya karta hai: Ek number ke bits ko invert karta hai. Matlab 1 ko 0 banata hai aur 0 ko 1.

Rule: Number ke bits ko invert karta hai.
# Bitwise NOT example a = 5 # 0101 in binary result = ~a print(result) # -6 (1111...1010 in binary)
-6
# Bitwise NOT example a = 3 result = ~a print(result) # -4 (1111...1100 in binary)
-4
Chapter 3: Membership Operators - Python

Part 6: Membership Operators

1. in

Kya karta hai: Yeh check karta hai ki ek element kisi sequence (list, string, tuple) mein hai ya nahi.

Rule: Sequence ke andar element ka hona zaroori hai.
# Membership 'in' operator example a = [1, 2, 3, 4] result = 3 in a print(result) # True
True
# Membership 'in' operator example a = [1, 2, 3, 4] result = 5 in a print(result) # False
False

2. not in

Kya karta hai: Yeh check karta hai ki ek element kisi sequence mein nahi hai.

Rule: Agar element sequence mein nahi hai, to result True hoga.
# Membership 'not in' operator example a = [1, 2, 3, 4] result = 5 not in a print(result) # True
True
# Membership 'not in' operator example a = [1, 2, 3, 4] result = 3 not in a print(result) # False
False
Chapter 3: Identity Operators - Python

Part 7: Identity Operators

1. is

Kya karta hai: Yeh check karta hai ki do variables ek hi object ko refer kar rahe hain ya nahi.

Rule: Agar dono variables ek hi memory address (object) ko point kar rahe hain, to result True hota hai.
# Identity 'is' operator example a = [1, 2, 3] b = a result = a is b print(result) # True
True
# Identity 'is' operator example a = [1, 2, 3] b = [1, 2, 3] result = a is b print(result) # False
False

2. is not

Kya karta hai: Yeh check karta hai ki do variables ek hi object ko refer nahi kar rahe hain.

Rule: Agar dono variables alag memory address (objects) ko point kar rahe hain, to result True hota hai.
# Identity 'is not' operator example a = [1, 2, 3] b = [1, 2, 3] result = a is not b print(result) # True
True
# Identity 'is not' operator example a = [1, 2, 3] b = a result = a is not b print(result) # False
False