1. Reading a Text File and Counting Words

with open('text_file.txt', 'r') as f:

Explanation

• open() is used to open a file.
• 'text_file.txt' is the file name.
• 'r' means read mode.
• with automatically closes the file after use.
• as f stores the file object in variable f.

content = f.read()

Explanation

• read() reads all text from the file.
• The text is stored in variable content.

Example:

If the file contains:

Hello world Python is easy

Then:

content = "Hello world Python is easy"

words = content.split()

Explanation

• split() breaks text into separate words.
• By default, it splits where spaces occur.

Example:

"Hello world Python".split()

becomes:

['Hello', 'world', 'Python']

So words becomes a list of words.

print(f"Number of words: {len(words)}")

Explanation

• len(words) counts total words in the list.
• f"" is an f-string used to insert values into text.

Example Output:

Number of words: 5

2. Handling Division by Zero Using try-except

try:

Explanation

• try is used to test code that may cause an error.

num1 = 10
num2 = 0

Explanation

Two variables are created:

• num1 = 10
• num2 = 0

result = num1 / num2

Explanation

This tries to divide:

$10 \div 0$

Division by zero is not allowed in Python.

So Python raises an error called:

ZeroDivisionError

print(result)

Explanation

• This would print the result.
• But it never runs because the error happens before it.

except ZeroDivisionError:

Explanation

• except catches the error.
• If a ZeroDivisionError occurs, Python runs this block instead of stopping the program.

print("Error: Division by zero")

Explanation

This prints a custom error message.

Output:

Error: Division by zero

3. Simple Note-Taker Program

with open('notes.txt', 'a') as f:

Explanation

• Opens the file notes.txt.
• 'a' means append mode.
• Append mode adds new data without deleting old data.

note = input("Enter a note: ")

Explanation

• input() asks the user to type something.
• The typed text is stored in variable note.

Example:

Enter a note: Study Python today

Then:

note = "Study Python today"

f.write(note + '\n')

Explanation

• write() saves text into the file.
• '\n' adds a new line after the note.

So every new note goes on a separate line.

Example file content:

Study Python today
Buy groceries
Complete homework

Final Concepts Used