Vinayagam

Posted on May 25

Building Strong Python Basics – Loops, Functions and Logic

#python #beginners #learning #codenewbie

My Learning Notes – Python Basics (Day Learning Blog)

Today’s class was focused on basic Python concepts and some logical problems. Even though the topics are simple, they form the foundation for programming. I am writing this blog to revise what I learned in my own words.

sep and end in Python

In Python, the print() function has default behavior:

It adds space between multiple values
It moves to the next line after printing

We can control this using sep and end.

sep (separator): used to define what comes between values
end: used to define what comes at the end of the output

Example:

print("hi", "hello", sep=" ", end="*")
print(5)

Output:

hi hello*5

This means:

sep=" " keeps space between words
end="*" prevents new line and adds * instead

This concept is useful when formatting output.

Functions in Python

A function is a reusable block of code designed to perform a specific task.

Instead of writing the same logic again and again, we use functions. This improves code readability and reduces duplication.

A function can take input values called arguments and can return output.

Arguments in Functions

Arguments are values passed to a function when it is called.

Types of arguments (basic idea):

Required arguments
Default arguments
Variable-length arguments

Arguments make functions flexible and reusable.

Polymorphism

Polymorphism means “many forms”.

In programming, it means:

A single function or operation behaves differently based on input

Example:

Adding two numbers → numeric addition
Adding two strings → string concatenation

So, same operation but different behavior.

Method Overloading

Method overloading means:

Same function name
Different number or type of arguments

Python does not support traditional method overloading like some languages, but we can achieve similar behavior using default arguments or conditions.

Sum of First n Natural Numbers

We learned a mathematical formula:

n(n + 1) / 2

This formula gives the sum of first n numbers.

Example:
For n = 10
Sum = 10 × 11 / 2 = 55

Using loop:

bag = 0 
day = 1
while day <= 10:
    bag = bag + day
    day = day + 1
print(bag)

This loop keeps adding numbers one by one.

Identity Elements in Mathematics

Two important concepts:

Additive Identity:
Adding 0 does not change the value
Example: 5 + 0 = 5
Multiplicative Identity:
Multiplying by 1 does not change the value
Example: 5 × 1 = 5

These are basic but important in logic building.

Multiplication of First n Numbers

This is similar to sum, but instead of addition we use multiplication.

total = 1
no = 1
while no <= 5:
    total = total * no
    no = no + 1
print(total)

Factorial Concept

Factorial of a number means multiplying all numbers from 1 to that number.

Example:
5! = 5 × 4 × 3 × 2 × 1

Code:

factorial = 1
no = 1
while no <= 5:
    factorial = factorial * no
    no = no + 1
print(factorial)

Reverse approach:

factorial = 1
no = 5
while no >= 1:
    factorial = factorial * no
    no = no - 1
print(factorial)

Both methods give the same result.

Logic Problem – Frog Climbing

This problem is about simulation using loops.

Given:

Frog starts at 50 feet
Climbs 2 feet every time
Slips down 1.25 feet

We need to find how many steps or days it takes.

feet = 50
up = 2
down = 1.25
day = 0

while feet > 0:
    feet = feet - up + down
    day = day + 1

print(day)

This type of problem improves logical thinking and loop understanding.

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