Python Programming Summary Note 

1. Introduction to Python

Python is a high-level programming language known for its simple syntax and readability. It is widely used in data analysis, artificial intelligence, automation, web development, and financial technology (FinTech).

Example:

print("Hello, World!")

Output:

Hello, World!

Explanation: The print() function displays information on the screen.

Practice: Write a program that displays your name and learning goal.

2. Variables and Data Types

A variable is a name used to store a value that can be used later in a program.

Example:

name = "Alex"
age = 20
balance = 150.50
is_student = True

print(name)
print(age)
print(balance)
print(is_student)

Output:

Alex
20
150.5
True

Common data types:

Key point: The = operator assigns a value to a variable.

Practice: Create variables for your name, age, monthly expenses, and student status. Display their values using print().

3. Operators

Operators perform calculations and comparisons in Python.

Common arithmetic operators:

Example:

income = 500
expenses = 320

savings = income - expenses

print(savings)

Output:

180

Explanation: The program subtracts expenses from income to calculate the remaining savings.

Practice: Calculate your total expenses by adding food, transportation, and study costs. Subtract the total from your monthly budget.

4. Conditional Statements

Conditional statements allow a program to make decisions based on specific conditions. Python uses if, elif, and else.

Example:

balance = 100

if balance >= 200:
    print("Sufficient balance")
elif balance >= 100:
    print("Minimum balance reached")
else:
    print("Low balance")

Output:

Minimum balance reached

Explanation:

• if checks the first condition.

• elif checks another condition if the previous condition is false.

• else executes when none of the previous conditions is true.

Practice: Write a program that checks whether a student's score is at least 50. Display "Pass" if the score is 50 or higher and "Fail" otherwise.

5. Loops

Loops repeat instructions without requiring the same code to be written multiple times. Python provides two commonly used loops: for and while.

5.1 For Loop

A for loop iterates over a sequence or a range of values.

Example:

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

Output:

1
2
3
4
5

Explanation:

• for starts the loop.

• number is the variable that stores the current value in each iteration.

• range(1, 6) generates numbers from 1 to 5. The ending value, 6, is excluded.

• print(number) displays each number on a separate line.

Practice: Write a for loop that displays numbers from 1 to 10.

5.2 While Loop

A while loop repeats instructions as long as its condition remains true.

Example:

count = 1

while count <= 3:
    print(count)
    count += 1

Output:

1
2
3

Explanation:

• count = 1 initializes the counter.

• while count <= 3 checks whether the condition is true.

• print(count) displays the current number.

• count += 1 increases the counter by one after each iteration.

Key point: A while loop needs a condition that eventually becomes false to prevent an infinite loop.

Practice: Write a while loop that displays numbers from 1 to 5.

6. Lists and Dictionaries

Lists and dictionaries are data structures used to store and organize information.

6.1 Lists

A list stores multiple items in a single variable.

Example:

expenses = [20, 35, 15, 40]

print(expenses[0])
print(sum(expenses))

Output:

20
110

Explanation:

• expenses stores four numerical values.

• expenses[0] accesses the first item because Python indexing starts at zero.

• sum(expenses) calculates the total of all numerical values.

Practice: Create a list containing five expenses and calculate their total.

6.2 Dictionaries

A dictionary stores information as key-value pairs.

Example:

student = {
    "name": "Alex",
    "age": 20,
    "major": "FinTech"
}

print(student["name"])
print(student["major"])

Output:

Alex
FinTech

Explanation:

• name, age, and major are keys.

• "Alex", 20, and "FinTech" are their corresponding values.

• student["name"] retrieves the value associated with the "name" key.

Key difference:

• Lists organize collections of items.

• Dictionaries organize information using keys associated with values.

Practice: Create a dictionary containing your name, major, and university year. Display each value.

7. Functions

A function is a reusable block of code designed to perform a specific task. Functions improve code organization and reduce repetition.

Example:

def calculate_savings(income, expenses):
    return income - expenses

result = calculate_savings(500, 320)

print(result)

Output:

180

Explanation:

• def defines a function.

• income and expenses are parameters.

• return sends the calculated result back to the caller.

• calculate_savings(500, 320) calls the function using two arguments.

• print(result) displays the returned value.

Practice: Create a function named calculate_total() that accepts three numbers and returns their sum.

8. Practical Project: Monthly Expense Tracker

This project combines variables, dictionaries, built-in functions, arithmetic operators, and conditional statements to create a simple expense tracker.

Objective: Calculate total monthly expenses and determine the remaining budget.

Code:

budget = 500

expenses = {
    "Food": 120,
    "Transport": 50,
    "Study": 80,
    "Entertainment": 40
}

total_expenses = sum(expenses.values())
remaining_balance = budget - total_expenses

print("Monthly Budget:", budget)
print("Total Expenses:", total_expenses)
print("Remaining Balance:", remaining_balance)

if remaining_balance >= 0:
    print("You are within your budget.")
else:
    print("You have exceeded your budget.")

Output:

Monthly Budget: 500
Total Expenses: 290
Remaining Balance: 210
You are within your budget.

Explanation:

1. budget stores the available monthly budget.

2. The expenses dictionary organizes spending by category.

3. expenses.values() retrieves the expense amounts.

4. sum() calculates the total expenses.

5. Arithmetic subtraction calculates the remaining balance.

6. The if-else statement checks whether the budget has been exceeded.

7. print() displays the results.

Extension exercises:

1. Add a new expense category.

2. Change the budget and expense amounts.

3. Calculate the average expense.

4. Display each expense category and its amount.

5. Display a warning when expenses exceed 80% of the budget.

9. Final Practice Challenge

Complete the following tasks independently to test your understanding of Python fundamentals.

1. Create variables for monthly income and expenses.

2. Calculate total expenses from a list of five items.

3. Use an if statement to check whether your savings are positive.

4. Write a function that calculates savings.

5. Extend the expense tracker by adding a new expense category.

6. Display each expense category and its amount.

Success criteria: The program should run without errors, produce correct calculations, and display understandable results.

10. Conclusion

Python programming begins with understanding fundamental concepts and applying them through regular practice. Variables, data types, operators, conditional statements, loops, data structures, and functions form the foundation of Python development. By combining these concepts in practical projects such as a monthly expense tracker, learners can develop problem-solving skills and prepare for more advanced applications in data analysis, automation, business analytics, and financial technology (FinTech).