🐍 PYTHON – DAY 6 STUDY MATERIAL
✨ Topic: while Loop in Python

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📌 What is a Loop?
A loop is used to repeat a block of code multiple times until a condition becomes False.

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🔁 What is while Loop?

The while loop executes a block of code as long as the condition is True.

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🔹 Syntax of while Loop

while condition:
statement
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🔹 Example: Print Numbers 1 to 5

i = 1
while i <= 5:
print(i)
i = i + 1
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🔹 Example: Sum of Numbers

i = 1
sum = 0
while i <= 5:
sum = sum + i
i = i + 1
print(sum)

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🔹 Infinite Loop
A loop that never ends is called an infinite loop.

Example (Avoid this):
while True:
print("Python")

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🔹 Common Mistakes in while Loop

❌ Forgetting to update loop variable
❌ Wrong condition
❌ Infinite loop

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📝 Practice Tasks – Day 6

✔ Print numbers from 1 to 10
✔ Print even numbers using while loop
✔ Find factorial of a number
✔ Reverse a number

Example Program:
num = int(input("Enter a number: "))
rev = 0
while num > 0:
digit = num % 10
rev = rev * 10 + digit
num = num // 10
print("Reverse:", rev)

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🎯 Day 6 Goal

✔ Understand repetition using while loop
✔ Avoid infinite loops

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📅 Next Topic – Day 7
🔥 for Loop in Python
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🐍 PYTHON – DAY 7 STUDY MATERIAL
✨ Topic: for Loop in Python

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📌 What is for Loop?
The for loop is used to iterate over a sequence such as a list, tuple, string, or range.

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🔹 Syntax of for Loop
for variable in sequence:
statement

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🔹 Using range() Function

range() generates a sequence of numbers.
range(start, stop, step)

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

Output:
1 2 3 4 5

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🔹 Example: Print Even Numbers

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

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🔹 Looping Through a String
for ch in "Python":
print(ch)

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🔹 Nested for Loop
A for loop inside another for loop.

Example:
for i in range(1, 4):
for j in range(1, 4):
print(i, j)

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🔹 Difference Between for and while Loop

• for loop is used when number of iterations is known
• while loop is used when condition is unknown

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📝 Practice Tasks – Day 7

✔ Print numbers from 1 to 10
✔ Print multiplication table
✔ Print characters of a string
✔ Create star pattern using nested loop

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

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🎯 Day 7 Goal
✔ Master iteration using for loop
✔ Use range() confidently

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📅 Next Topic – Day 8
🔥 break, continue & pass Statements
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🐍 PYTHON – DAY 8 STUDY MATERIAL
✨ Topic: break, continue & pass Statements
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📌 Control Statements in Python

Control statements are used to change the normal flow of loops.
Python provides three control statements:

• break
• continue
• pass

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🛑 break Statement

The break statement is used to terminate the loop immediately when a condition is met.

Example:
for i in range(1, 10):
if i == 5:
break
print(i)
Output:
1 2 3 4

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⏭ continue Statement

The continue statement skips the current iteration and moves to the next one.

Example:
for i in range(1, 6):
if i == 3:
continue
print(i)
Output:
1 2 4 5

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⏸ pass Statement

The pass statement is used as a placeholder where a statement is required but no action is needed.

Example:
for i in range(1, 5):
if i == 2:
pass
print(i)

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🔍 Difference Between break, continue & pass

• break → Stops loop completely
• continue → Skips current iteration
• pass → Does nothing, avoids error

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📝 Practice Tasks – Day 8

✔ Stop loop when number equals 7
✔ Skip printing number 5
✔ Use pass inside empty if block
✔ Combine loop with break & continue

Example Program:
for i in range(1, 11):
if i == 5:
continue
if i == 8:
break
print(i)

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🎯 Day 8 Goal
✔ Control loop execution
✔ Understand loop flow clearly

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📅 Next Topic – Day 9
🔥 Pattern Programs (Stars & Numbers)
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React ❤️ If You Got It Right

🐍 PYTHON – DAY 9 STUDY MATERIAL
✨ Topic: Pattern Programs (Stars & Numbers)

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📌 What are Pattern Programs?

Pattern programs use loops and logic to print designs using stars (*) or numbers.
They help improve loop control and logical thinking.

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⭐ Star Pattern – Right Triangle

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

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⭐ Star Pattern – Inverted Triangle

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

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⭐ Pyramid Star Pattern

Code:
n = 4
for i in range(n):
print(" " * (n - i - 1) + "*" * (2 * i + 1))

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🔢 Number Pattern – Increasing Numbers

1
12
123
1234

Code:
for i in range(1, 5):
for j in range(1, i + 1):
print(j, end="")
print()
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🔢 Number Pattern – Same Number

1
22
333
4444

Code:
for i in range(1, 5):
print(str(i) * i)

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💡 Logic Tips for Pattern Programs

✔ Outer loop → rows
✔ Inner loop → columns
✔ Spaces control alignment
✔ Practice regularly

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📝 Practice Tasks – Day 9

✔ Print hollow star rectangle
✔ Print number pyramid
✔ Print reverse number pattern
✔ Create your own pattern

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🎯 Day 9 Goal
✔ Master nested loops
✔ Improve logical thinking

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📅 Next Topic – Day 10
🔥 Functions in Python (Basics)
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🐍 PYTHON – DAY 10 STUDY MATERIAL
✨ Topic: Functions in Python (Basics)

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📌 What is a Function?

A function is a block of reusable code that performs a specific task.
Functions help reduce code repetition and improve readability.

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🔹 Why Use Functions?

✔ Code reusability
✔ Better organization
✔ Easy debugging
✔ Saves time and effort

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🧩 Syntax of a Function

def function_name():
statement

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🔹 Example: Simple Function

def greet():
print("Hello Python")
greet()
Output:
Hello Python

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🔹 Function with Parameters
Parameters are values passed to a function.

Example:
def greet(name):
print("Hello", name)
greet("Soham")

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🔹 Function with Return Value

The return statement sends a value back to the caller.

Example:
def add(a, b):
return a + b
result = add(10, 20)
print(result)

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🔹 Function Call

Calling a function means executing it.
Example:
add(5, 3)

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⚠️ Important Points

• Function name should be meaningful
• Use indentation properly
• return ends the function execution

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📝 Practice Tasks – Day 10

✔ Create a function to print your name
✔ Create a function to add two numbers
✔ Create a function to find square of a number
✔ Create a function to check even or odd

Example Program:
def square(n):
return n * n
print(square(5))

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🎯 Day 10 Goal
✔ Understand function basics
✔ Write reusable code

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📅 Next Topic – Day 11
🔥 Function Arguments (Types)
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🐍 PYTHON – DAY 11 STUDY MATERIAL
✨ Topic: Function Arguments (Types)

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📌 What are Function Arguments?

Arguments are values passed to a function when it is called.
They allow functions to work with different inputs.

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🔹 1. Positional Arguments

Arguments are passed in the same order as parameters.

Example:
def add(a, b):
print(a + b)
add(10, 5)

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🔹 2. Keyword Arguments

Arguments are passed using parameter names, order does not matter.

Example:
def greet(name, msg):
print(msg, name)
greet(msg="Hello", name="Soham")

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🔹 3. Default Arguments

Default values are used when no argument is passed.

Example:
def greet(name="User"):
print("Hello", name)
greet()
greet("Python")
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🔹 4. Variable-Length Arguments (*args)

Used when number of arguments is unknown.

Example:
def total(*nums):
print(sum(nums))
total(10, 20, 30)

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🔹 5. Keyword Variable-Length Arguments

Used to pass key-value pairs.

Example:
def details(**info):
print(info)
details(name="Soham", age=20)

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⚠️ Important Notes

• Positional arguments come first
• Default arguments should be last
• *args → tuple
• **kwargs → dictionary

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📝 Practice Tasks – Day 11

✔ Use positional & keyword arguments
✔ Create function with default value
✔ Create function using *args
✔ Create function using **kwargs

Example Program:
def marks(*m):
print(sum(m))
marks(60, 70, 80)

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🎯 Day 11 Goal
✔ Understand all types of function arguments
✔ Write flexible functions

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📅 Next Topic – Day 12
🔥 Recursion in Python
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🐍 PYTHON – DAY 12 STUDY MATERIAL
✨ Topic: Recursion in Python

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📌 What is Recursion?

Recursion is a technique where a function calls itself to solve a problem.
It is useful for problems that can be broken into smaller sub-problems.

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🔹 Two Important Parts of Recursion

1️⃣ Base Condition – Stops recursion
2️⃣ Recursive Call – Function calls itself
Without base condition → infinite recursion ❌

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🔹 Syntax of Recursive Function

def function_name():
if base_condition:
return value
return function_name(smaller_problem)

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🔢 Example: Factorial using Recursion

def factorial(n):
if n == 1:
return 1
return n * factorial(n - 1)
print(factorial(5))

Output:
120

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🔁 Example: Fibonacci Series

def fib(n):
if n <= 1:
return n
return fib(n - 1) + fib(n - 2)
print(fib(6))

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⚠️ Important Notes

• Always define a base case
• Recursive calls increase memory usage
• Not suitable for very large problems

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📝 Practice Tasks – Day 12

✔ Find factorial of a number
✔ Print Fibonacci series
✔ Calculate sum of digits using recursion
✔ Reverse a number using recursion

Example Program:
def sum_digits(n):
if n == 0:
return 0
return n % 10 + sum_digits(n // 10)
print(sum_digits(123))

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🎯 Day 12 Goal
✔ Understand recursive thinking
✔ Write correct recursive functions

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📅 Next Topic – Day 13
🔥 Strings in Python
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🐍 PYTHON – DAY 13 STUDY MATERIAL
✨ Topic: Strings in Python

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📌 What is a String?

A string is a sequence of characters enclosed in single (' ') or double (" ") quotes.

Example:
name = "Python"
msg = 'Hello'

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🔢 String Indexing

Each character in a string has an index number, starting from 0.

Example:
text = "Python"
text[0] → P
text[1] → y
text[-1] → n

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✂️ String Slicing
Used to extract a portion of a string.

Syntax:
string[start:end]

Example:
text = "Python"
print(text[0:3]) # Pyt
print(text[2:]) # thon
print(text[:4]) # Pyth

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🔁 String Looping

Example:
for ch in "Python":
print(ch)

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🧮 String Length
Use len() to find string length.

Example:
text = "Python"
print(len(text))

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🔒 Strings are Immutable

Strings cannot be changed once created.

Example:
text = "Python"
text[0] = 'J' ❌ Error

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📝 Practice Tasks – Day 13

✔ Print each character of a string
✔ Reverse a string
✔ Find length of a string
✔ Extract substring

Example Program:
text = input("Enter a string: ")
print(text[::-1])

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🎯 Day 13 Goal
✔ Understand string basics
✔ Use indexing and slicing confidently

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📅 Next Topic – Day 14
🔥 String Methods
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🐍 PYTHON – DAY 14 STUDY MATERIAL
✨ Topic: String Methods in Python

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📌 What are String Methods?

String methods are built-in functions used to manipulate and format strings.

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🔤 Common String Methods

🔹 upper() – Converts string to uppercase

Example:
text = "python"
print(text.upper())

🔹 lower() – Converts string to lowercase
print(text.lower())

🔹 title() – Capitalizes first letter of each word
print("hello world".title())

🔹 capitalize() – Capitalizes first character
print("python".capitalize())

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✂️ Trim Methods

🔹 strip() – Removes spaces from both sides
🔹 lstrip() – Removes left spaces
🔹 rstrip() – Removes right spaces

Example:
text = " python "
print(text.strip())

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🔁 Replace & Split

🔹 replace() – Replaces part of string
print("hello python".replace("python", "world"))

🔹 split() – Splits string into list
print("a,b,c".split(","))

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🔍 Search Methods

🔹 find() – Returns index of substring
print("python".find("t"))

🔹 count() – Counts occurrences
print("banana".count("a"))

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❓ Check Methods

🔹 isalpha() – Checks alphabets
🔹 isdigit() – Checks digits
🔹 isalnum() – Checks alphanumeric

Example:
print("Python123".isalnum())

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📝 Practice Tasks – Day 14
✔ Convert string to uppercase
✔ Count vowels in string
✔ Replace a word in sentence
✔ Split full name into first and last name

Example Program:
text = input("Enter text: ")
print(text.upper())

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🎯 Day 14 Goal
✔ Master common string methods
✔ Manipulate strings effectively

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📅 Next Topic – Day 15
🔥 Lists in Python
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🐍 PYTHON – DAY 15 STUDY MATERIAL
✨ Topic: Lists in Python

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📌 What is a List?

A list is a collection of items stored in a single variable.
Lists are ordered, mutable (changeable) and allow duplicate values.

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🔹 Creating a List

Example:
nums = [10, 20, 30, 40]
names = ["Python", "Java", "C"]

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🔢 List Indexing

Example:
nums = [10, 20, 30]
nums[0] → 10
nums[-1] → 30

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✂️ List Slicing

Example:
nums = [1, 2, 3, 4, 5]
print(nums[1:4]) # [2, 3, 4]

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✏️ Modify List Elements

Example:
nums = [10, 20, 30]
nums[1] = 25
print(nums)

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🔁 Looping Through List

Example:
for n in nums:
print(n)

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🧮 List Length

Example:
print(len(nums))

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📝 Practice Tasks – Day 15

✔ Create a list of numbers
✔ Access elements using index
✔ Change list elements
✔ Print all list elements using loop

Example Program:
nums = [5, 10, 15, 20]
for n in nums:
print(n)

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🎯 Day 15 Goal
✔ Understand list basics
✔ Use lists confidently

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📅 Next Topic – Day 16
🔥 List Methods
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🐍 PYTHON – DAY 16 STUDY MATERIAL
✨ Topic: List Methods in Python

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📌 What are List Methods?

List methods are built-in functions used to add, remove, and manage list elements.

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➕ Adding Elements

🔹 append() – Adds element at the end
Example:
nums = [1, 2, 3]
nums.append(4)

🔹 insert() – Adds element at specific index
nums.insert(1, 10)

🔹 extend() – Adds multiple elements
nums.extend([5, 6])

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➖ Removing Elements

🔹 remove() – Removes specific value
nums.remove(10)

🔹 pop() – Removes element by index
nums.pop()
nums.pop(1)

🔹 clear() – Removes all elements
nums.clear()
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🔄 Other Useful List Methods

🔹 sort() – Sorts list
nums.sort()

🔹 reverse() – Reverses list
nums.reverse()

🔹 count() – Counts occurrence
nums.count(2)

🔹 index() – Returns index of value
nums.index(3)

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🧠 List Copy

🔹 copy() – Creates shallow copy
new_list = nums.copy()

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⚠️ Important Notes

• Lists are mutable
• sort() changes original list
• Use sorted() to keep original list

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📝 Practice Tasks – Day 16

✔ Add elements using append & insert
✔ Remove elements using pop & remove
✔ Sort a list
✔ Reverse a list

Example Program:
nums = [4, 2, 1, 3]
nums.sort()
print(nums)

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🎯 Day 16 Goal
✔ Master list operations
✔ Manage list data efficiently

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📅 Next Topic – Day 17
🔥 Tuples in Python
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🐍 PYTHON – DAY 17 STUDY MATERIAL
✨ Topic: Tuples in Python

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📌 What is a Tuple?

A tuple is a collection of items stored in a single variable.
Tuples are ordered and immutable (cannot be changed).

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🔹 Creating a Tuple

Example:
t = (10, 20, 30)
names = ("Python", "Java", "C")
Single element tuple:
x = (10,) ✔ comma is required

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🔢 Tuple Indexing

Example:
t = (10, 20, 30)
t[0] → 10
t[-1] → 30

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✂️ Tuple Slicing

Example:
t = (1, 2, 3, 4, 5)
print(t[1:4])

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🔁 Looping Through Tuple

Example:
for item in t:
print(item)

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🔒 Tuple Immutability
Tuple elements cannot be modified.

Example:
t = (10, 20, 30)
t[0] = 5 ❌ Error

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🧮 Tuple Methods

🔹 count() – Counts occurrence
🔹 index() – Returns index

Example:
t = (1, 2, 2, 3)
print(t.count(2))
print(t.index(3))

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🔄 Convert Tuple to List

Example:
t = (1, 2, 3)
lst = list(t)

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📝 Practice Tasks – Day 17

✔ Create tuple of numbers
✔ Access elements using index
✔ Loop through tuple
✔ Convert tuple to list

Example Program:
t = (5, 10, 15)
for i in t:
print(i)

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🎯 Day 17 Goal
✔ Understand tuple basics
✔ Know difference between list & tuple

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📅 Next Topic – Day 18
🔥 Sets in Python
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🐍 PYTHON – DAY 18 STUDY MATERIAL
✨ Topic: Sets in Python

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📌 What is a Set?

A set is a collection of unique elements stored in a single variable.
Sets are unordered and do not allow duplicate values.

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🔹 Creating a Set

Example:
s = {10, 20, 30}
names = {"Python", "Java", "C"}
Duplicate values are removed automatically:
s = {1, 2, 2, 3}
Output → {1, 2, 3}

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➕ Add Elements to Set

🔹 add() – Adds single element
s.add(40)

🔹 update() – Adds multiple elements
s.update([50, 60])
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➖ Remove Elements from Set

🔹 remove() – Removes element (error if not found)
s.remove(20)

🔹 discard() – Removes element (no error)
s.discard(100)

🔹 pop() – Removes random element
s.pop()

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🔄 Set Operations

🔹 union() – Combines sets
🔹 intersection() – Common elements
🔹 difference() – Remaining elements

Example:
a = {1, 2, 3}
b = {3, 4, 5}
print(a.union(b))
print(a.intersection(b))
print(a.difference(b))

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🧮 Check Membership

Example:
print(2 in a)

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📝 Practice Tasks – Day 18

✔ Create a set
✔ Add and remove elements
✔ Perform union & intersection
✔ Remove duplicate values from list using set

Example Program:
lst = [1, 2, 2, 3, 4]
s = set(lst)
print(s)

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🎯 Day 18 Goal
✔ Understand set properties
✔ Perform set operations

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📅 Next Topic – Day 19
🔥 Dictionaries in Python
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🐍 PYTHON – DAY 19 STUDY MATERIAL
✨ Topic: Dictionaries in Python

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📌 What is a Dictionary?

A dictionary stores data in key–value pairs.
Dictionaries are unordered, mutable, and keys must be unique.

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🔹 Creating a Dictionary

Example:
student = {
"name": "Soham",
"age": 20,
"course": "Python"
}

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🔑 Access Dictionary Values

Example:
print(student["name"])
print(student.get("age"))

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✏️ Modify Dictionary

Example:
student["age"] = 21
student["city"] = "Pune"

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❌ Remove Dictionary Items

🔹 pop() – Removes specific key
student.pop("city")

🔹 popitem() – Removes last item
student.popitem()

🔹 clear() – Removes all items
student.clear()

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🔁 Loop Through Dictionary

Example:
for key in student:
print(key, student[key])

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🧮 Dictionary Methods

🔹 keys() – Returns all keys
🔹 values() – Returns all values
🔹 items() – Returns key-value pairs

Example:
print(student.keys())
print(student.values())

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📝 Practice Tasks – Day 19

✔ Create student dictionary
✔ Add and update values
✔ Loop through dictionary
✔ Delete a key

Example Program:
student = {"name": "Amit", "age": 22}
for k, v in student.items():
print(k, v)

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🎯 Day 19 Goal
✔ Understand key-value storage
✔ Use dictionaries effectively

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📅 Next Topic – Day 20
🔥 Dictionary Methods & Nested Dictionary
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🐍 PYTHON – DAY 20 STUDY MATERIAL
✨ Topic: Dictionary Methods & Nested Dictionary

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📌 Important Dictionary Methods

🔹 update() – Adds or updates key-value pairs

Example:
student = {"name": "Soham"}
student.update({"age": 21})

🔹 get() – Returns value of key
print(student.get("name"))

🔹 setdefault() – Returns value, adds key if not present
student.setdefault("city", "Pune")

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❌ Removing Dictionary Data

🔹 del – Deletes key
del student["age"]

🔹 clear() – Removes all data
student.clear()

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🧩 Nested Dictionary

A dictionary inside another dictionary is called a nested dictionary.

Example:
students = {
1: {"name": "Amit", "age": 20},
2: {"name": "Soham", "age": 21}
}
Access nested value:
print(students[1]["name"])

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🔁 Loop Through Nested Dictionary

Example:
for id, info in students.items():
print(id, info["name"], info["age"])

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🧮 Copy Dictionary

🔹 copy() – Creates shallow copy
new_dict = student.copy()

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📝 Practice Tasks – Day 20

✔ Use update() and setdefault()
✔ Create nested dictionary
✔ Access and print nested values
✔ Loop through nested dictionary

Example Program:
data = {1: {"name": "Raj", "marks": 80}}
print(data[1]["marks"])

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🎯 Day 20 Goal
✔ Master dictionary methods
✔ Work with nested dictionaries

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📅 Next Topic – Day 21
🔥 Revision + Practice (Week Review)
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🐍 PYTHON – DAY 21 STUDY MATERIAL
✨ Topic: Revision + Practice (Week Review)

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📌 Topics Covered (Day 1 – Day 20)

✔ Python Introduction & Installation
✔ Variables & Data Types
✔ Operators
✔ Conditional Statements
✔ while Loop & for Loop
✔ break, continue, pass
✔ Pattern Programs
✔ Functions & Arguments
✔ Recursion
✔ Strings & String Methods
✔ Lists & List Methods
✔ Tuples
✔ Sets
✔ Dictionaries & Nested Dictionary

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🧠 Quick Revision Points

🔹 Variables are dynamically typed
🔹 Indentation is mandatory in Python
🔹 Lists are mutable, tuples are immutable
🔹 Sets store unique values
🔹 Dictionaries store key-value pairs
🔹 Functions reduce code repetition

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🧪 Practice Programs – Day 21

1️⃣ Check whether a number is even or odd

num = int(input("Enter number: "))
if num % 2 == 0:
print("Even")
else:
print("Odd")

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2️⃣ Find sum of elements in a list

nums = [10, 20, 30]
print(sum(nums))

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3️⃣ Reverse a string

text = input("Enter string: ")
print(text[::-1])

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4️⃣ Count frequency using dictionary

text = "python"
freq = {}
for ch in text:
freq[ch] = freq.get(ch, 0) + 1
print(freq)

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⭐ Challenge Tasks

✔ Print star pyramid
✔ Create simple calculator using functions
✔ Remove duplicates from list
✔ Store student data using dictionary

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🎯 Day 21 Goal
✔ Revise all fundamentals
✔ Identify weak topics
✔ Build confidence in basics

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📅 Next Topic – Day 22
🔥 File Handling in Python
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🐍 PYTHON – DAY 22 STUDY MATERIAL
✨ Topic: File Handling in Python

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📌 What is File Handling?

File handling allows Python programs to read data from files and write data to files permanently.

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📂 Types of Files

✔ Text files (.txt)
✔ Binary files (.bin, .dat)

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📁 Opening a File

Syntax:
file = open("filename", "mode")
Common modes:
"r" → Read
"w" → Write
"a" → Append
"x" → Create
"rb" → Read binary
"wb" → Write binary

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📖 Reading from a File

Example:
file = open("data.txt", "r")
print(file.read())
file.close()

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✍️ Writing to a File

Example:
file = open("data.txt", "w")
file.write("Hello Python")
file.close()

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➕ Append Data to File

Example:
file = open("data.txt", "a")
file.write("\nWelcome")
file.close()

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🔒 Using with Statement
Automatically closes the file.

Example:
with open("data.txt", "r") as file:
print(file.read())

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📝 Practice Tasks – Day 22

✔ Create a text file
✔ Write data into file
✔ Read file content
✔ Append data to file

Example Program:
with open("test.txt", "w") as f:
f.write("Python File Handling")

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🎯 Day 22 Goal
✔ Understand file operations
✔ Read & write files safely

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📅 Next Topic – Day 23
🔥 File Methods & File Modes
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🐍 PYTHON – DAY 23 STUDY MATERIAL
✨ Topic: File Methods & File Modes

━━━━━━━━━━━━━━━━━━━

📌 File Modes in Python

🔹 "r" – Read mode (file must exist)
🔹 "w" – Write mode (creates new / overwrites file)
🔹 "a" – Append mode (adds data at end)
🔹 "x" – Create file (error if file exists)
🔹 "r+" – Read + Write
🔹 "w+" – Write + Read

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📖 Important File Methods

🔹 read() – Reads entire file
🔹 readline() – Reads one line
🔹 readlines() – Reads all lines as list

Example:
with open("data.txt", "r") as f:
print(f.readline())

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✍️ Writing Multiple Lines

Example:
with open("data.txt", "w") as f:
f.writelines(["Python\n", "Java\n", "C\n"])

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📍 File Cursor Position

🔹 tell() – Returns current position
🔹 seek() – Changes position

Example:
with open("data.txt", "r") as f:
print(f.tell())
f.seek(0)

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🧹 Closing a File

🔹 close() – Closes file manually
🔹 with statement – Closes automatically (recommended)

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⚠️ Common File Errors

❌ FileNotFoundError
❌ PermissionError
❌ Wrong mode usage

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📝 Practice Tasks – Day 23

✔ Read file line by line
✔ Write multiple lines to file
✔ Use tell() and seek()
✔ Try different file modes

Example Program:
with open("demo.txt", "w+") as f:
f.write("Hello Python")
f.seek(0)
print(f.read())

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🎯 Day 23 Goal
✔ Master file modes
✔ Use file methods confidently

━━━━━━━━━━━━━━━━━━━

📅 Next Topic – Day 24
🔥 Exception Handling (try, except)
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🐍 PYTHON – DAY 24 STUDY MATERIAL
✨ Topic: Exception Handling in Python

━━━━━━━━━━━━━━━━━━━

📌 What is an Exception?

An exception is an error that occurs during program execution, which interrupts normal flow.
Examples:
ZeroDivisionError
ValueError
TypeError

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🛡 Why Use Exception Handling?

✔ Prevent program crash
✔ Handle errors gracefully
✔ Improve program reliability

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🔹 try-except Block

Syntax:
try:
risky_code
except:
error_handling_code

Example:
try:
x = int(input("Enter number: "))
print(10 / x)
except:
print("Error occurred")

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🔹 Handling Specific Exceptions

Example:
try:
print(10 / 0)
except ZeroDivisionError:
print("Cannot divide by zero")

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🔹 Multiple except Blocks

Example:
try:
x = int(input())
except ValueError:
print("Invalid input")
except ZeroDivisionError:
print("Division error")

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🔹 else Block
Executes if no exception occurs.

Example:
try:
print(10 / 2)
except:
print("Error")
else:
print("Success")

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🔹 finally Block
Always executes (used for cleanup).

Example:
try:
print(10 / 2)
finally:
print("Done")

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📝 Practice Tasks – Day 24

✔ Handle divide by zero
✔ Handle invalid input
✔ Use else and finally
✔ Write safe calculator

Example Program:
try:
a = int(input("Enter a: "))
b = int(input("Enter b: "))
print(a / b)
except Exception as e:
print("Error:", e)

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🎯 Day 24 Goal
✔ Handle runtime errors
✔ Write crash-free programs

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📅 Next Topic – Day 25
🔥 User-Defined Exceptions
✨ Stay Connected | Keep Coding
🚀 TechByWebCoder

🐍 PYTHON – DAY 25 STUDY MATERIAL
✨ Topic: User-Defined Exceptions

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📌 What is a User-Defined Exception?

User-defined exceptions are custom errors created by programmers to handle specific situations.

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🧩 Why Use Custom Exceptions?

✔ Clear error messages
✔ Better control over program flow
✔ Easy debugging

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🔹 Creating a Custom Exception

Custom exceptions are created by inheriting from Exception class.

Example:
class AgeError(Exception):
pass

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🔹 Raising a Custom Exception

Example:
def check_age(age):
if age < 18:
raise AgeError("Age must be 18 or above")
else:
print("Eligible")

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🔹 Handling Custom Exception

Example:
try:
check_age(16)
except AgeError as e:
print(e)

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🔹 Using raise Keyword

The raise keyword is used to trigger an exception manually.

Example:
raise ValueError("Invalid value")

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⚠️ Important Notes

• Custom exceptions should be meaningful
• Always handle raised exceptions
• Use inheritance properly

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📝 Practice Tasks – Day 25

✔ Create custom exception for login failure
✔ Raise exception for invalid marks
✔ Handle custom exception using try-except

Example Program:
class MarksError(Exception):
pass
marks = int(input("Enter marks: "))
if marks < 0 or marks > 100:
raise MarksError("Invalid marks")

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🎯 Day 25 Goal
✔ Understand custom exception creation
✔ Handle program-specific errors

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📅 Next Topic – Day 26
🔥 Modules in Python
✨ Stay Connected | Keep Coding
🚀 TechByWebCoder