April Python Bootcamp Day 3

 

 

Introduction

In Python, operators are fundamental building blocks used to perform operations on variables and values. Whether you're building a calculator, writing conditions, or designing logic — operators are everywhere.

Key Insight:
Operators are the backbone of decision-making and computation in programming.

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 What is an Operator?

An operator is a symbol that performs an operation on operands (values or variables).

a = 10
b = 5
print(a + b)  # Output: 15

• + → Operator
• a, b → Operands

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 Why Operators Matter

Operators are used in:

•  Calculations → price + tax
•  Conditions → age > 18
•  Logic → is_logged_in and is_verified
•  Control flow → loops, decisions

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 Types of Operators in Python

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 1. Arithmetic Operators

Used for mathematical operations.

print(10 + 5)   # 15
print(10 - 5)   # 5
print(10 * 5)   # 50
print(10 / 5)   # 2.0
print(10 // 3)  # 3
print(10 % 3)   # 1
print(2 ** 3)   # 8

Notes:

• / → always returns float
• // → floor division
• % → useful for even/odd checks

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 2. Assignment Operators

Used to assign and update values.

x = 10
x += 5   # 15
x -= 2   # 13
x *= 2   # 26
x /= 2   # 13.0

Notes:

• Short-hand operations improve readability
• Common in loops and updates

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 3. Comparison Operators

Used to compare values → returns Boolean

print(10 == 10)  # True
print(10 != 5)   # True
print(10 > 5)    # True
print(10 < 5)    # False

Notes:

• Always returns True or False
• Used in conditions (if, loops)

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 4. Logical Operators

Combine multiple conditions

print(True and False)  # False
print(True or False)   # True
print(not True)        # False

Notes:

• and → all conditions must be True
• or → at least one True
• not → reverses result

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 5. Identity Operators

Check if two variables refer to the same object

a = [1, 2]
b = a
c = [1, 2]

print(a is b)   # True
print(a is c)   # False
print(a == c)   # True

Notes:

• is → checks memory location
• == → checks value

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 6. Membership Operators

Check if a value exists in a sequence

print("a" in "apple")     # True
print(10 in [1, 2, 3])    # False
print(1 in (1, 2, 3))     # True

Notes:

• Works with strings, lists, tuples, sets

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 Operator Precedence

Precedence determines which operator executes first.

print(2 + 3 * 4)  # 14

 Multiplication happens before addition

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 Associativity

Associativity determines evaluation order when precedence is same.

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 Left to Right

print(10 - 5 - 2)  # 3

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 Right to Left

print(2 ** 3 ** 2)  # 512

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 Precedence + Associativity Table

Priority	Operators	Associativity
1	()	Left → Right
2	**	Right → Left
3	+x, -x, not	Right → Left
4	* / // %	Left → Right
5	+ -	Left → Right
6	Comparisons	Left → Right
7	and	Left → Right
8	or	Left → Right
9	Assignment	Right → Left

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 Important Notes (Exam / Interview Level)

• True = 1, False = 0
• and returns first falsy value
• or returns first truthy value
• is ≠ ==
• Exponent is right-associative
• Division always returns float

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 Practice Questions (NEW – Not Repeated)

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 Q1

print(8 + 2 * 5 - 3)

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 Q2

print(20 // 3 + 2 ** 2)

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 Q3

print(5 > 3 and 8 < 5 or 10 > 2)

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 Q4

print(not (4 == 4 and 2 > 3))

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 Q5

x = 10
x -= 3 * 2
print(x)

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 Q6

print(6 + 3 * 2 ** 2)

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 Q7

print("p" in "python" and 5 not in [1,2,3])

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 Q8

a = [1,2,3]
b = a
c = a[:]

print(a is c)

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 Q9

print(0 or 5 and 10)

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 Q10 (Advanced)

print(2 ** 2 ** 3 + 1)