Operators, Expressions and Python Statements – NIELIT O Level (M3-R5)

💡 Introduction

Python में Assignment Statement का प्रयोग किसी variable को value देने के लिए किया जाता है। यह statement memory में data store करने का तरीका बताता है।

🧩 Syntax

variable_name = value
  

यहाँ = एक assignment operator है जो right side की value को left side variable में store करता है।

📘 Examples

x = 10
y = 20
z = x + y
print("Sum =", z)
    

a, b, c = 5, 10, 15
print(a, b, c)
    

x = y = z = 100
print(x, y, z)
    

🔍 Flowchart Logic

1. Start
2. Initialize variable
3. Assign value to variable
4. Use variable in expression
5. Display output
6. Stop

⚙️ Types of Assignment

• Simple Assignment → x = 10
• Multiple Assignment → a, b = 5, 10
• Chained Assignment → x = y = z = 20
• Augmented Assignment → x += 5 (means x = x + 5)

x = 10
x += 5   # same as x = x + 5
print("New value of x =", x)
    

🧠 Key Points

• Python में variable declare करते समय datatype specify नहीं करना पड़ता।
• Assignment operator right-to-left काम करता है।
• Multiple और chained assignments एक ही line में values assign करने देते हैं।
• Augmented operators code को short और clean बनाते हैं।

🧩 Summary

• Assignment Statement variable को value देने के लिए use होता है।
• ‘=’ operator assignment के लिए प्रयोग किया जाता है।
• Python में Multiple और Augmented assignment supported हैं।

💡 Introduction

Expression Python का एक बहुत ही महत्वपूर्ण हिस्सा है। Expression किसी value या result को produce करने वाला logical combination होता है जिसमें operands (values or variables) और operators शामिल होते हैं। जैसे गणित में हम लिखते हैं 2 + 3 × 4 — Python में यही concept code के रूप में लागू होता है।

🧩 Example (Basic Expression)

x = 10
y = 5
z = x + y * 2
print("Result =", z)
  

यहाँ Python पहले multiplication (y * 2) करेगा, फिर addition (x + ...)। यानी Operator Precedence rule follow होता है।

📘 Flowchart Logic

1. Start
2. Initialize variables
3. Perform operations (Arithmetic / Logical / etc.)
4. Store result in variable
5. Display output
6. Stop

⚙️ Types of Expressions in Python

• 1️⃣ Arithmetic Expression
• 2️⃣ Relational (Comparison) Expression
• 3️⃣ Logical Expression
• 4️⃣ Bitwise Expression
• 5️⃣ Assignment Expression
• 6️⃣ String Expression
• 7️⃣ Compound Expression

1️⃣ Arithmetic Expressions

Arithmetic expressions में +, -, *, /, %, //, ** जैसे operators का प्रयोग होता है। ये mathematical calculations करने के लिए उपयोगी हैं।

a = 15
b = 4
print("Addition:", a + b)
print("Subtraction:", a - b)
print("Multiplication:", a * b)
print("Division:", a / b)
print("Floor Division:", a // b)
print("Modulus:", a % b)
print("Exponent:", a ** b)
  

2️⃣ Relational (Comparison) Expressions

Relational expressions दो values की तुलना करते हैं और True या False result return करते हैं। Operators: >, <, ==, !=, >=, <=

x = 10
y = 20
print("x == y:", x == y)
print("x != y:", x != y)
print("x > y:", x > y)
print("x < y:", x < y)
print("x >= y:", x >= y)
print("x <= y:", x <= y)
  

3️⃣ Logical Expressions

Logical expressions का उपयोग multiple conditions को combine करने के लिए किया जाता है। Operators हैं: and, or, not.

a = 10
b = 20
c = 5

print(a > b and b > c)   # False
print(a < b or b < c)    # True
print(not(a < b))        # False
  

4️⃣ Bitwise Expressions

Bitwise operators binary digits (0 और 1) पर काम करते हैं। Operators: &, |, ^, ~, <<, >>

x = 5    # 0101
y = 3    # 0011

print("AND:", x & y)
print("OR:", x | y)
print("XOR:", x ^ y)
print("NOT x:", ~x)
print("Left Shift:", x << 1)
print("Right Shift:", x >> 1)
  

5️⃣ Assignment Expressions

Assignment expression value को variable में store करने के लिए प्रयोग होता है। Example: x = 10, x += 2, (n := len(list)) (walrus operator)।

x = 10
x += 5
print("x =", x)

# Walrus Operator (Python 3.8+)
if (n := len("Hello")) > 3:
    print("Length is:", n)
  

6️⃣ String Expressions

जब operators को strings पर use किया जाता है तो उन्हें string expressions कहते हैं। Example: concatenation (+), repetition (*).

name = "Python"
greet = "Hello " + name
print(greet)

line = "Hi! " * 3
print(line)
  

7️⃣ Compound Expressions

Compound expressions में एक से अधिक operators और sub-expressions combine होते हैं। Example: (a + b) * (c - d) / e

a, b, c, d, e = 10, 5, 8, 3, 2
result = (a + b) * (c - d) / e
print("Result =", result)
  

📊 Operator Precedence (Highest to Lowest)

🧠 Real-Life Examples

• 📱 Arithmetic: Calculator applications
• ⚖️ Relational: Age comparison for voting eligibility
• 🔒 Logical: Login authentication (username & password)
• 🧾 String: Dynamic message creation and UI labels

🧩 Summary

• Expressions produce a result by combining variables, constants, and operators.
• Python supports many types — Arithmetic, Logical, Relational, Bitwise, String.
• Operator precedence decides execution order.
• Parentheses () are used to control evaluation order.
• Expressions are the building blocks of all Python programs.

💡 Introduction

Arithmetic Operators का प्रयोग गणितीय (mathematical) operations करने के लिए किया जाता है जैसे – जोड़ (addition), घटाना (subtraction), गुणा (multiplication), भाग (division) आदि। Python में arithmetic operators integer, float, और complex data types पर काम करते हैं।

📘 List of Arithmetic Operators

🧩 Flowchart Logic

1. Start
2. Input two numbers
3. Apply operator (e.g., +, -, *, /, ...)
4. Store result in variable
5. Display output
6. Stop

⚙️ Example 1 – Basic Arithmetic Operations

a = 10
b = 4

print("Addition:", a + b)
print("Subtraction:", a - b)
print("Multiplication:", a * b)
print("Division:", a / b)
print("Floor Division:", a // b)
print("Modulus:", a % b)
print("Exponent:", a ** b)
  

🧮 Example 2 – Arithmetic with Variables

x = int(input("Enter first number: "))
y = int(input("Enter second number: "))

sum = x + y
diff = x - y
prod = x * y
quot = x / y
rem = x % y

print("Sum =", sum)
print("Difference =", diff)
print("Product =", prod)
print("Quotient =", quot)
print("Remainder =", rem)
  

🧠 Example 3 – Compound Arithmetic Expression

a, b, c = 10, 5, 2
result = (a + b) * c ** 2 / 5
print("Result =", result)
  

🧩 Example 4 – Average of Three Numbers

a = float(input("Enter first number: "))
b = float(input("Enter second number: "))
c = float(input("Enter third number: "))

avg = (a + b + c) / 3
print("Average =", avg)
  

🔢 Example 5 – Calculate Simple Interest

p = float(input("Enter Principal: "))
r = float(input("Enter Rate of Interest: "))
t = float(input("Enter Time (years): "))

si = (p * r * t) / 100
print("Simple Interest =", si)
  

🧮 Example 6 – Swap Two Numbers Using Arithmetic

a = 5
b = 7

a = a + b
b = a - b
a = a - b

print("After Swapping: a =", a, ", b =", b)
  

🧩 Example 7 – Convert Temperature

celsius = float(input("Enter temperature in Celsius: "))
fahrenheit = (celsius * 9/5) + 32
print("Temperature in Fahrenheit =", fahrenheit)
  

📊 Operator Precedence (Order of Execution)

⚙️ Example 8 – Precedence Test

x = 5 + 3 * 2 ** 2
print(x)
  

🧩 Real-Life Applications

• Finance apps → Interest, EMI, Loan calculations
• Engineering → Area, volume, formula computations
• Gaming → Score calculation and animation logic
• Science → Unit conversion (Celsius ↔ Fahrenheit)

🧠 Practice Corner

• ✅ Write a Python program to find area and perimeter of a rectangle.
• ✅ Calculate compound interest using formula.
• ✅ Find average of n numbers entered by user.

🧩 Summary

• Arithmetic operators perform mathematical computations.
• Operators follow a fixed precedence order.
• Expressions can be simple or compound.
• Used everywhere — from basic calculation to real-world apps.

💡 Introduction

Relational (या Comparison) Operators का उपयोग दो values की तुलना (comparison) करने के लिए किया जाता है। इन operators का result हमेशा True या False होता है। ये decision making (जैसे if statements) में बहुत उपयोगी होते हैं।

📊 List of Relational Operators

🧩 Flowchart Logic

1. Start
2. Input two numbers (A, B)
3. Apply comparison (A > B, A == B, etc.)
4. Decision: True / False
5. Display result
6. Stop

⚙️ Q&A Based Examples

a = 10
b = 10
print(a == b)
    

a = 15
b = 20
print(a != b)
    

print(8 > 5)
    

print(12 < 9)
    

print(7 >= 7)
    

print(2 <= 10)
    

print("apple" < "banana")
    

print("A" < "a")
    

print(True > False)
    

print([1, 2, 3] < [1, 3, 0])
    

marks = int(input("Enter marks: "))
if marks >= 40:
    print("Pass")
else:
    print("Fail")
    

a = 12
b = 8
if a > b:
    print("A is greater")
else:
    print("B is greater")
    

age = int(input("Enter your age: "))
if age >= 18:
    print("Eligible for voting.")
else:
    print("Not eligible.")
    

n = int(input("Enter number: "))
if 10 <= n <= 50:
    print("Within range")
else:
    print("Out of range")
    

a = "HELLO"
b = "hello"
print(a.lower() == b.lower())
    

📘 Operator Precedence (In Comparisons)

• All comparison operators have equal precedence.
• They are evaluated from left to right.
• Multiple comparisons can be chained: a < b < c

a, b, c = 5, 10, 15
print(a < b < c)
    

🧠 Real-Life Applications

• 🔐 User authentication (password match)
• 🎓 Grade classification (marks ≥ criteria)
• ⚙️ Conditional execution in programs
• 📊 Data filtering and sorting in databases

📈 Practice Corner

• ✅ Write a program to compare three numbers and print the largest.
• ✅ Check if a number is positive, negative, or zero.
• ✅ Input marks and print grade according to range.
• ✅ Compare two strings alphabetically and show which comes first.

🧩 Summary

• Relational operators always return boolean values (True/False).
• Used in if, while, and filtering conditions.
• Strings and lists can also be compared lexicographically.
• They form the foundation of all decision-making logic in Python.

💡 Introduction

Logical Operators का प्रयोग conditions को जोड़ने या उनके result को manipulate करने के लिए किया जाता है। Python में 3 मुख्य logical operators होते हैं: and, or, और not। ये expressions का boolean (True/False) result देते हैं और decision making में अत्यंत उपयोगी होते हैं।

📊 List of Logical Operators

🧩 Flowchart Logic

1. Start
2. Input two conditions
3. Apply logical operator (and/or/not)
4. Generate True/False result
5. Display result
6. Stop

⚙️ Q&A Based Examples

a = 10
b = 5
print(a > b and b < 10)
    

x = 8
print(x < 5 or x == 8)
    

a = 10
print(not(a > 5))
    

n = 15
print(n > 10 and n < 20)
    

marks = 60
attendance = 80
if marks >= 40 and attendance >= 75:
    print("Pass")
else:
    print("Fail")
    

n = 0
if n > 0 or n == 0:
    print("Positive or Zero")
else:
    print("Negative")
    

n = 7
print(not (n % 2 == 0))
    

username = "admin"
password = "1234"

if username == "admin" and password == "1234":
    print("Login Successful")
else:
    print("Invalid credentials")
    

n = 10
if n % 3 == 0 or n % 5 == 0:
    print("Divisible by 3 or 5")
else:
    print("Not divisible")
    

age = 17
if age >= 13 and age <= 19:
    print("Teenager")
else:
    print("Not a Teenager")
    

a = "Hello"
b = "HELLO"
print(a.lower() == b.lower() and len(a) == len(b))
    

x, y, z = 5, 10, 15
print(x < y and y < z or z == 15)
    

a = 10
b = 5
print(not(a < b and a != b))
    

n = 120
if not(50 <= n <= 100):
    print("Out of range")
else:
    print("Within range")
    

a, b, c = True, False, True
print(a and not b or c)
    

📘 Operator Precedence (Logical)

• not → Highest
• and → Middle
• or → Lowest

x = True or False and not False
print(x)
    

🧠 Real-Life Applications

• 🔐 Login validation (username & password check)
• 🎓 Eligibility checking (age ≥ 18 and nationality == "Indian")
• 🧮 Range-based filters in data
• ⚙️ Complex condition handling in automation

📈 Practice Corner

• ✅ Write a program to check if year is leap year (divisible by 4 and not by 100 or divisible by 400).
• ✅ Input two numbers and print whether both are even or both are odd.
• ✅ Check if entered character is vowel or consonant.
• ✅ Create a login system using `and` and `not` operators.

🧩 Summary

• Logical operators control multiple boolean expressions.
• They return True or False only.
• Precedence: not > and > or.
• Used widely in decision making and looping.

💡 Introduction

Bitwise Operators का प्रयोग integers के binary bits पर operation करने के लिए किया जाता है। ये operators direct bits (0s और 1s) पर काम करते हैं, इसलिए ये बहुत fast और efficient होते हैं। Bitwise operators का उपयोग low-level programming, encryption, और device control में किया जाता है।

📊 List of Bitwise Operators

🧩 Binary Representation

  Decimal : 5 → Binary : 0101
  Decimal : 3 → Binary : 0011
  

⚙️ Q&A Based Examples

a = 5  # 0101
b = 3  # 0011
print(a & b)
    

print(5 | 3)
    

print(5 ^ 3)
    

print(~5)
    

print(5 << 1)
    

print(5 >> 1)
    

a = 12  # 1100
b = 25  # 11001
print(a & b)
    

x, y = 7, 3
print((x & y) | (x ^ y))
    

n = 13      # 1101
mask = 1<<2 # 0100
print(n & ~mask)
    

n = 9       # 1001
mask = 1<<1 # 0010
print(n | mask)
    

n = 10      # 1010
mask = 1<<1 # 0010
print(n ^ mask)
    

print(4 << 3)
    

print(20 >> 2)
    

n = 14
if n & 1 == 0:
    print("Even")
else:
    print("Odd")
    

a, b = 5, 7
a = a ^ b
b = a ^ b
a = a ^ b
print(a, b)
    

📘 Operator Precedence (Bitwise)

🧠 Real-Life Applications

• 🧮 Fast arithmetic (multiplication/division by powers of 2)
• 💾 Data encryption / compression
• ⚙️ Device control (bit flags, sensors)
• 🧠 Memory-efficient programming

📈 Practice Corner

• ✅ Write a program to count set bits (1s) in binary representation of a number.
• ✅ Create a mask to turn on/off bits 0, 2, and 4.
• ✅ Check if a number is power of two using bitwise AND.
• ✅ Reverse bits of an integer using shifts and masks.

🧩 Summary

• Bitwise operators work directly on bits (binary digits).
• Useful for optimization and low-level hardware logic.
• Shifts act like multiply/divide by powers of 2.
• XOR is often used in cryptography and swapping values.

💡 Introduction

Conditional Statements का प्रयोग किसी condition के आधार पर decision लेने के लिए किया जाता है। Python में यह control flow को manage करने का सबसे महत्वपूर्ण हिस्सा है। ये statements किसी condition के True या False होने पर अलग-अलग code block execute करते हैं।

📊 Types of Conditional Statements in Python

• if statement
• if-else statement
• if-elif-else ladder
• nested if
• short-hand if (single line)

🧩 Syntax

if condition:
    statement(s)
elif another_condition:
    statement(s)
else:
    statement(s)
  

🧭 Flowchart Logic

1. Start
2. Evaluate condition
3. If True → execute body
4. If False → skip or go to else
5. End

⚙️ Q&A Based Examples

num = 10
if num > 0:
    print("Positive number")
    

num = -5
if num >= 0:
    print("Positive")
else:
    print("Negative")
    

n = 7
if n % 2 == 0:
    print("Even")
else:
    print("Odd")
    

a, b = 10, 20
if a > b:
    print("A is greater")
else:
    print("B is greater")
    

a, b, c = 30, 20, 10
if a > b and a > c:
    print("A is largest")
elif b > c:
    print("B is largest")
else:
    print("C is largest")
    

marks = 45
if marks >= 40:
    print("Pass")
else:
    print("Fail")
    

marks = 85
if marks >= 90:
    print("Grade A+")
elif marks >= 75:
    print("Grade A")
elif marks >= 60:
    print("Grade B")
elif marks >= 40:
    print("Grade C")
else:
    print("Fail")
    

age = 17
if age >= 18:
    print("Eligible for voting")
else:
    print("Not eligible")
    

year = 2024
if year % 4 == 0:
    if year % 100 == 0:
        if year % 400 == 0:
            print("Leap Year")
        else:
            print("Not Leap Year")
    else:
        print("Leap Year")
else:
    print("Not Leap Year")
    

n = 35
if 10 <= n <= 50:
    print("In range")
else:
    print("Out of range")
    

ch = 'e'
if ch.lower() in ['a', 'e', 'i', 'o', 'u']:
    print("Vowel")
else:
    print("Consonant")
    

a = 5
b = 10
print("A is greater") if a > b else print("B is greater")
    

num = 15
if num % 3 == 0 and num % 5 == 0:
    print("Multiple of 3 and 5")
else:
    print("Not multiple of both")
    

ch = '7'
if ch.isdigit():
    print("Digit")
elif ch.isalpha():
    print("Alphabet")
else:
    print("Special Character")
    

user = "admin"
pwd = "1234"
if user == "admin" and pwd == "1234":
    print("Access Granted")
else:
    print("Access Denied")
    

📘 Operator Precedence in Conditions

• Relational Operators (==, <, >) evaluated before Logical (and, or, not)
• Parentheses () can override precedence

🧠 Real-Life Applications

• 🎓 Grade calculation and pass/fail logic
• 🔐 Login systems and access control
• ⚙️ Automated decision-making systems
• 🧮 Checking input values and validation

📈 Practice Corner

• ✅ Write a program to check if number is divisible by 2, 3, or both.
• ✅ Check if entered year is leap or not (using nested if).
• ✅ Input marks and print grade using if-elif-else ladder.
• ✅ Check whether character is uppercase, lowercase, digit, or special symbol.

🧩 Summary

• Conditional statements decide which code block executes.
• if executes only if condition is True.
• if-elif-else handles multiple conditions.
• Nested if allows checking within conditions.
• Short-hand if used for compact one-line decisions.

💡 Introduction

Looping statements का प्रयोग तब किया जाता है जब किसी code block को बार-बार दोहराना (repeat) हो। Python में मुख्य दो प्रकार के loops होते हैं — for loop और while loop। इसके अलावा loops को nested (एक loop के अंदर दूसरा loop) भी बनाया जा सकता है।

📊 Types of Loops in Python

• for loop – sequence (list, tuple, string, range) पर iterate करता है
• while loop – जब तक condition True है, code चलता रहता है
• nested loop – एक loop के अंदर दूसरा loop

🧩 Syntax

# for loop
for variable in sequence:
    statement(s)

# while loop
while condition:
    statement(s)
  

🧭 Flowchart Logic

1. Start
2. Initialize counter variable
3. Check condition
4. If True → Execute body → Update counter
5. If False → Exit loop
6. Stop

⚙️ Q&A Based Examples

for i in range(1, 6):
    print(i)
    

i = 1
while i <= 5:
    print(i)
    i += 1
    

for i in range(2, 11, 2):
    print(i)
    

sum = 0
for i in range(1, 11):
    sum += i
print("Sum =", sum)
    

for i in range(1, 11):
    print("5 x", i, "=", 5*i)
    

s = "Python"
for ch in reversed(s):
    print(ch, end="")
    

for ch in "HELLO":
    print(ch)
    

n = 5
fact = 1
while n > 0:
    fact *= n
    n -= 1
print("Factorial =", fact)
    

i = 1
while i <= 10:
    print(i)
    i += 1
    

n = int(input("Enter number: "))
for i in range(1, 11):
    print(n, "x", i, "=", n*i)
    

num = 1234
sum = 0
while num > 0:
    digit = num % 10
    sum += digit
    num //= 10
print("Sum =", sum)
    

for i in range(1, 6):
    print("*" * i)
    

for i in range(5, 0, -1):
    print("*" * i)
    

for i in range(1, 4):
    for j in range(1, 6):
        print(i, "x", j, "=", i*j)
    print("-----------")
    

for i in range(1, 51):
    if i % 3 == 0 and i % 5 == 0:
        print(i)
    

for i in range(1, 11):
    if i == 6:
        break
    print(i)
    

for i in range(1, 10):
    if i % 2 == 0:
        continue
    print(i)
    

s = 0
for i in range(1, 6):
    s += i*i
print("Sum of squares =", s)
    

# WARNING: Infinite Loop
while True:
    print("Hello")
    break  # prevents actual infinity
    

a, b = 0, 1
for i in range(10):
    print(a, end=" ")
    a, b = b, a + b
    

📘 Loop Control Statements

• break → stops loop immediately
• continue → skips current iteration
• pass → null statement (used as placeholder)

🧠 Real-Life Applications

• 🧮 Table generation and number series
• 🎓 Pattern printing and result analysis
• 📊 Data iteration (lists, files, strings)
• ⚙️ Automation and repetitive tasks

📈 Practice Corner

• ✅ Print sum of all even numbers between 1 and 100.
• ✅ Create a number pyramid using nested loops.
• ✅ Find factorial of given number using for loop.
• ✅ Reverse a number using while loop.

🧩 Summary

• Loops help in repeating code efficiently.
• for → sequence iteration, while → condition-based repetition.
• Nested loops → patterns and tables.
• break, continue, pass → control loop flow.

💡 Introduction

Python में Loop Control Statements का प्रयोग loop के normal flow को बदलने के लिए किया जाता है। इनका उपयोग loop को रोकने, किसी iteration को skip करने या future code के लिए placeholder के रूप में किया जाता है।

📊 Types of Loop Control Statements

🧭 Flowchart Logic

1. Start Loop
2. Check condition
3. If break → Exit loop
4. If continue → Skip to next iteration
5. If pass → Do nothing
6. End

⚙️ Q&A Based Examples

🔹 Break Statement

for i in range(1, 11):
    if i == 5:
        break
    print(i)
    

nums = [12, 45, -8, 33, 90]
for n in nums:
    if n < 0:
        print("First negative =", n)
        break
    

count = 1
while count <= 5:
    print(count)
    if count == 3:
        break
    count += 1
    

nums = [10, 20, 30, 40]
target = 30
for n in nums:
    if n == target:
        print("Found", n)
        break
    

🔹 Continue Statement

for i in range(1, 10):
    if i % 2 == 0:
        continue
    print(i)
    

for i in range(1, 8):
    if i == 5:
        continue
    print(i)
    

nums = [12, -7, 8, 0, -2, 15]
for n in nums:
    if n <= 0:
        continue
    print(n)
    

for ch in "PYTHON":
    if ch in "AEIOU":
        continue
    print(ch, end="")
    

marks = [75, 20, 55, 38, 90]
for m in marks:
    if m < 40:
        continue
    print("Passed with", m)
    

🔹 Pass Statement

for i in range(5):
    pass  # future logic here
print("Loop executed successfully.")
    

num = 5
if num > 0:
    pass
else:
    print("Negative number")
    

def future_task():
    pass
print("Function created successfully.")
    

🔹 Mixed Control Flow Examples

for i in range(1, 11):
    if i == 7:
        break
    print(i)
    

for i in range(1, 21):
    if i == 15:
        break
    if i % 2 == 0:
        continue
    print(i)
    

for i in range(1, 6):
    if i == 3:
        pass
    else:
        print("Processing:", i)
    

📘 Difference Summary Table

🧠 Real-Life Applications

• 🎯 Skipping invalid data entries (using continue)
• 🚫 Exiting search loop when result found (using break)
• 📋 Reserving structure for future logic (using pass)

📈 Practice Corner

• ✅ Write a program to print 1–100 but stop when number = 73.
• ✅ Skip all multiples of 3 and 5 between 1–50.
• ✅ Use pass to create empty function templates for future code.

🧩 Summary

• break → immediately exits loop.
• continue → skips current iteration.
• pass → does nothing (acts as a null statement).
• All three make loops flexible and powerful.

💡 Introduction

जब एक loop के अंदर दूसरा loop होता है, उसे Nested Loop कहा जाता है। Nested loops का प्रयोग patterns, matrices, tables और complex data traversal के लिए किया जाता है। हर outer loop के अंदर inner loop कई बार execute होता है।

📊 Syntax

for i in range(outer_limit):
    for j in range(inner_limit):
        # inner loop statements
  

🧭 Flowchart Logic

1. Start
2. Outer loop initialization
3. Inner loop runs completely
4. Outer loop increments
5. Repeat until condition False
6. Stop

⭐ STAR PATTERN PROGRAMS

for i in range(1, 6):
    for j in range(1, i + 1):
        print("*", end="")
    print()
    

for i in range(5, 0, -1):
    for j in range(i):
        print("*", end="")
    print()
    

for i in range(1, 6):
    print(" " * (5 - i) + "*" * i)
    

for i in range(1, 6):
    print(" " * (5 - i) + "*" * (2*i - 1))
    

n = 5
for i in range(1, n + 1):
    print(" " * (n - i) + "*" * (2*i - 1))
for i in range(n - 1, 0, -1):
    print(" " * (n - i) + "*" * (2*i - 1))
    

🔢 NUMBER PATTERN PROGRAMS

for i in range(1, 6):
    for j in range(1, i + 1):
        print(j, end="")
    print()
    

for i in range(1, 6):
    for j in range(1, i + 1):
        print(i, end="")
    print()
    

for i in range(5, 0, -1):
    for j in range(1, i + 1):
        print(j, end="")
    print()
    

for i in range(1, 6):
    print(" " * (5 - i), end="")
    for j in range(1, i + 1):
        print(j, end="")
    for j in range(i - 1, 0, -1):
        print(j, end="")
    print()
    

🅰️ ALPHABET PATTERN PROGRAMS

for i in range(65, 70):  # ASCII A=65
    for j in range(65, i + 1):
        print(chr(j), end="")
    print()
    

for i in range(1, 6):
    print(" " * (5 - i), end="")
    for j in range(65, 65 + i):
        print(chr(j), end="")
    print()
    

for i in range(69, 64, -1):
    for j in range(65, i + 1):
        print(chr(j), end="")
    print()
    

💠 SPECIAL PATTERNS

n = 5
for i in range(n):
    for j in range(n):
        if i == 0 or i == n - 1 or j == 0 or j == n - 1:
            print("*", end="")
        else:
            print(" ", end="")
    print()
    

n = 5
for i in range(n):
    for j in range(n):
        if i == j or i + j == n - 1:
            print("*", end="")
        else:
            print(" ", end="")
    print()
    

for i in range(1, 6):
    for j in range(1, i + 1):
        print((i + j) % 2, end="")
    print()
    

🧠 Real-Life Applications

• 🎨 Creating visual patterns and animations
• 🧮 Matrix and grid-based logic
• 📊 Data representation in tabular form
• 💡 Logical problem-solving in interviews

📈 Practice Corner

• ✅ Create a hollow pyramid pattern of stars.
• ✅ Print Pascal’s triangle using nested loops.
• ✅ Print numbers in diamond shape.
• ✅ Print checkerboard (chessboard) pattern using * and space.

🧩 Summary

• Nested loops = loops inside another loop.
• Used for printing patterns, grids, tables, etc.
• Outer loop controls rows, inner loop controls columns.
• Best topic for logical & pattern-based coding questions.

ये FAQs Python के Nested Loops और Pattern Programs पर आधारित हैं — जो आजकल O Level, College Exams और Interviews में सबसे ज्यादा पूछे जाते हैं।

for i in range(outer_limit):
    for j in range(inner_limit):
        print(i, j)
    

for i in range(3):
    j = 0
    while j < 3:
        print(i, j)
        j += 1