If you want to become a data scientist 👨‍💻, you must be good at working with datasets. Being familiar with datasets is the first step toward building ML models.

Before working with data from the dataset it’s important to divide the dataset into three parts.

• Training: Used for training the model.
• Validation: Used to pick the best model for prediction. Once you have trained and tested various models, you must decide which model makes accurate predictions based on the validation set.
• Testing set: Once you have finalized the model you can then test the model with a testing set.

The ratio in which you divide the data depends on the size of the dataset and there is no specified number on how to split the data. However, you can generally split the dataset into 60% training, 20% validation, and 20% testing sets.

Originally published at https://liongueststudios.com on April 8, 2023.

Splitting The Dataset In Machine Learning was originally published in The Shortform on Medium, where people are continuing the conversation by highlighting and responding to this story.

There was a women named Natalia living in India. She was a software engineer by profession. One day she was doing her work at her home during the pandemic and at that time she got the news that a person in her building died because of some severe disease. As soon as she got this news she felt sad about it and she became a little anxious. Throughout the day she was constantly thinking of this news. As time passed, she started creating an illusion of the news in her brain and kept herself in the center of it. And she started thinking what if this situation happens to any of her close relatives? Because of this, she started becoming more fearful.

At night, her heartbeats started to increase rapidly due to anxiety of thinking negatively that what if someone from her known one dies. But after doing a little bit of walking and breathing exercises she started feeling a little normal. For the next week or so her heart used to beat faster than it normally does due to fear of death. Natalia thought these things might be happening because of some problems in her heart and so she thought of consulting a doctor.

Later she took an appointment with the doctor. The doctor checked her and performed an ECG test. In the test, everything was normal. Then the doctor checked the blood pressure and it seems higher than the normal range. The fear in Natalia’s mind gave rise to the increase in blood pressure. The doctor gave her some medicines and later she was feeling a little bit better.

One day, she was skimming through YouTube videos where she was exposed to the philosophy of stoicism. She then started learning more about the stoic philosophy by reading various books and watching videos related to the stoic philosophers like Marcus Aurelius, Epictetus, Seneca, Zeno, etc, and followed their teachings. As Marcus Aurelius said:

“The happiness of your life depends upon the quality of your thoughts.” — Marcus Aurelius

When we change the way we see the world and keep a balance between happiness and sufferings then this can lead us to a stable mind which will help us in achieving greatness. This can be done by mastering the mind.

She had a question of how to become mentally stable? Natalia found out that doing meditation and yoga could help her become mentally stable as well as relaxed. She understood that its not easy to master the mind and so she started to work on herself by practicing yoga and meditation.

After practicing yoga and meditation for few days she also got inclined towards spirituality and she started reading the “Shrimad Bhagwat Geeta” (a holy manuscript of Hindus). This holy book made her understand the importance and the position of the living entities (humans) in this universe. The chapter 2, verse 57 of the “Shrimad Bhagwat Geeta” says:

यः सर्वत्रानभिस्नेहस्तत्तत्प्राप्य श‍ुभाश‍ुभम् ।
नाभिनन्दति न द्वेष्टि तस्य प्रज्ञा प्रतिष्ठिता ॥ ५७ ॥

Meaning, A person living in this material world who is unaffected by any situation either good or bad, neither appreciates it or despise it, is fixed in perfect knowledge.

In the end, she came to realize that one thing that is common in all of such philosophies and spiritual books is that the only way to get rid of fear and anxiety is to become mentally stable and free from all the attachments of this material world.

The thing which you all can learn from this essay is that life is a journey which consists of combination of various experiences (some are good, some are bad) the only thing which we humans can do is to enjoy the trip.

This blog is originally published on my website: LionGuest Studios.com

Understanding the Data structures is the most crucial and important thing when it comes to learning and working with any programming language. Python too has some of the most popular data structures using which you can organize the data in memory. List, Tuples, Sets, and Dictionary are some of the widely used data structures in python. We will discuss the List data structure in python in detail.

List In Python

• The List is a data structure in python which stores data linearly or sequentially one after the other. It is somewhat similar to arrays in other programming languages.
• The only difference between an array and a List is the arrays can store data of the same type whereas Python’s List can store data with multiple data types (a combination of integer, string, floating-point, etc).
• Lists are represented using square brackets [ ]. The initial item in a list starts with an index number ‘0’.
• The list is a mutable data structure which simply means that once it has created the items inside which can be changed later.

Creating a list in Python

Lists can be created by putting values inside the square brackets and assigning it to a variable.

empty_list = [ ]

Here, empty_list is the name of the variable which will contain a list as represented by square brackets. And inside the square brackets, you don’t have any elements which simply means that the list is empty.

Examples:

list_of_numbers = [ 1, 2, 3, 4, 5] 
list_of_Strings = ['Ana', 'Pat', 'Simon', 'Amanda']

Note that the strings inside the list are represented by quotes (single or double quotes anything will work) and numbers have no quotation mark.

list_with_different_data_types = [ 'Micheal', 15, 20.5, [1, 2, 3] ]

This is a list that contains multiple data types. Also, the lists can contain another list too. In this case, element number 3 is an element of a list which is a list in itself.

Adding elements to a list in Python

There are two ways in which you can add an element to a list. The extend() function will be discussed later in this blog post.

1. append() function:

If you want to insert an element at the end of the list then you can use the append function. Inside this function, you have to pass the value or the element that needs to be inserted in a list.

original_lst = ['A', 'B', 'C', 'D', 'E'] 
original_lst.append('F') #This will insert element 'F' at the end of the list print(original_lst)

Output: 
['A', 'B', 'C', 'D', 'E', 'F']

You can even insert an entire list to an already created list with the append() function.

lst = ['A', 'B', 'C', 'D', 'E'] 
new_lst = ['F', 'G', '1', '2', '3'] 
lst.append(new_lst) print(lst)

Output: 
['A', 'B', 'C', 'D', 'E', ['F', 'G', '1', '2', '3']]

Note: If you want to add a single element to a list then use append() and if you want to add multiple elements into a list then use extend(). Go to extend() function.

2. insert() function:

If you want to insert an element at a specified location in a list then you can use the insert(location, element_to_insert) function which takes two parameters. In the first parameter, you have to pass the location at which the element is to be inserted and in the second parameter, you have to pass the value of the element.

my_list = ['one', 'three']

Now let’s add element ‘two’ to the above list at index 1 for that you have to use the insert function.

my_list( 1, 'two' )

After inserting the element ‘two’ at index 1, the element which is currently present at that location will be moved to the next index (in this case at index 2).

Output: 
['one', 'two', 'three']

Deleting elements from a list in Python

1. remove() function:

If you want to delete a particular element from a list using its value then you can use the remove() function. For example, if you want to remove element ‘ B ‘ from the list then you have to pass this as an argument to the remove() function.

list = ['A', 'B', 'C', 'D', 'E'] 
list.remove('B') print(list)

Output: ['A', 'C', 'D', 'E']

2. del keyword:

If you want to delete a particular element from a list using its index then you can use the del keyword. Let say you want to delete ‘Marry’ from the below list then you can delete that element using its index no.

list = ['Merry', 'Adam', 'Watson', 'Anna'] 
del list[0] #passing index 0 because Marry is present at the index print(list)

Output: ['Adam', 'Watson', 'Anna']

3. pop() function:

The pop() function works the same way as the del keyword but the only difference is that the pop() function will also return the element which has been deleted from the list.

list = ['Merry', 'Adam', 'Watson', 'Anna']item_popped = list.pop(0) print(item_popped) print(list)

Output: Marry ['Adam', 'Watson', 'Anna']

So, If you want to delete an element from a list in python using the value then use the remove() function. And if you want to delete an element using index no then use the del keyword or pop() function. In case if you also want to get the item that you have deleted then use the pop() function which will return you that item.

Accessing elements inside aList (Indexing) in Python

Each element in a list as an index no starting with zero. To find an element inside the list you have to use its index no. Accessing an element using its index no is called indexing. This can be done by passing the index number inside the square brackets.

list[indexNo]

In the below list, if you want to access the individual elements inside a list then you can pass the index as follows.

my_list = ['one', 'two','three'] 
print(my_list[0]) # accessing element 'one' 
print(my_list[1]) # accessing element 'two' 
print(my_list[2]) # accessing element 'three'

Output: 
one 
two 
three

Slicing a list in Python

Slicing is nothing but dividing a list. In case if you want to print some part of the list and not the entire list then you can use slicing.

Slicing is done using “:” colon symbol. It has 3 parts list[ start : end : stepSize ]. Step size is optional.

Let’s take an example and understand this.

slice_this_list = [10, 20, 30, 40, 50, 60]

So, to slice them you have to use the index number of both the start and the end elements. The index of starting element 20 is 1 and the index of ending element 50 is 4. You will use these index nos in order to slice the list.

print(slice_this_list[1 : 4])

What do you think it will print? It will print 20, 30, 40 only 3 elements. But we also want to print 50, right? The last element is not included in the slicing because python will exclude the end and will stop at one index before the end i.e in this case index 3.

To read the full blog post visit: LionGuestStudios.com

That’s all it is. Thanks for the read. If you like the content then support us on Patreon. Your support will surely help us in writing more of such content.

To read more such blogs about Python programming related stuff visit our blogs page on LionGuest Studios.

Originally published at https://liongueststudios.com.