Getting Started with Excel : From Basics to Data Cleaning

Gloriah John — Sun, 30 Aug 2026 21:42:32 +0000

Introduction

Data has become one of the main things we interact with in our daily lives. For data to be analyzed and used in making meaningful decisions, it has to be organized and cleaned. One of the key tools which happens to be one of my favorites is Microsoft Excel.

Microsoft Excel is basically an application made up of spreadsheets where one can enter, organize, calculate and analyze data.

This article provides friendly beginner introduction to Excel starting with the basics up to preparing our data for analysis through data cleaning.

1. Excel Environment

Excel has different parts to it. They include;

Ribbon

It is a collection of commands and tools.

Rows

Is a collection of cells that run horizontally in a worksheet. They are numbered 1,2,3, etc.

Columns

Is a collection of cells that run vertically in a worksheet. They are lettered A,B,C etc.

Cells

A cell is an intersection of a row and column.

Formula Bar

An area where the contents of the cell are displayed. It is very useful when working with formulas because it allows one to see the exact formula used.

Quick Access Toolbar

Located at the top left corner of Excel. It provides frequently used commands which are ;
. Save
. Undo
. Redo

Worksheet

It is an individual page in an Excel Workbook where data is entered and organized. A worksheet can be renamed.
Example: If you have a workbook for analyzing employee details you could have
Sheet 1: Employee Details, Sheet 2: Cleaned Data, Sheet 3: Analysis

2.Data Entry

To enter data, you type whatever information you want displayed in the cells as shown below:

To prevent errors in our data entry we can use a feature called Data Validation which controls the type of data one can enter into a cell.
For Example: If the employee's salary is between 30000 - 120000, data validation prevents values less than 30000 and greater than 120000 from being entered.

3. Data Cleaning

Data Cleaning is a vital step when it comes to data analysis. Quality of the intended results depends very much on the quality of the data being analyzed. Data cleaning ensures we get quality data for analysis.

Common problems found in excel datasets include;

Missing values
Duplicate records
Spelling errors
Incorrect data types
Inconsistent capitalization
Extra spaces

Missing Values

A very easy way of identifying missing values in a dataset is by applying the filter feature to a column. If there is a missing value the (Blanks)option will be selected as shown below:

To correct that, one can:

Enter the correct data needed.
Deleting the record
Leaving the cell as it is (blank) where there is no reliable value to enter.

Duplicate records

Duplicate record occur when the same information appears more than once in a dataset.

To remove duplicates, Excel provides a Remove Duplicates feature in the ribbon under the data Tab

Spelling errors

Spelling errors occur when words are entered incorrectly.

To correct that you can use the Find and Replace feature

Incorrect Data Types

Data type is basically the kind of value stored in a cell. This includes text, numbers, dates and percentages.
For example, if a the salary column is supposed to contain numbers, entering an employee's salary a text can pause a problem in data analysis

To correct that, one can select the affected cells and change the data type to the correct one.

Inconsistent Capitalization

Data my contain inconsistent capitalization as shown:

ndegwA
NDEGWA
Ndegwa

To correct the inconsistency, we use the PROPER function. In a cell type:
PROPER(A6) A6 being the cell with the inconsistency

On the same note the following functions also come in very handy;

LOWER() function which converts text in the chosen cell to Lowercase
UPPER() function which converts text in the chosen cell to Uppercase

Extra Spaces

Extra spaces can mainly occur when data is copied from another source or entered manually.
For Example:

"Ndegwa"
" Ndegwa'

To correct such, we use the TRIM 'function. In a cell typeTRIM(A6)`A6 being the cell with the issue.

4. Sorting and Filtering

These are very key functions in Excel.
Sorting changes the order in which records are displayed while Filtering displays only the records that meet a certain condition.
Below is raw data

Below is the sorted data

To sort:

Select inside the table you want to sort
Go to the Data tab
Select Sort
Select the desired order you want whether it is Smallest to Largest or Largest to smallest
Click Sort

Below is Raw data

Below is the Filtered data

To filter:

Select the column you want to filter
Go to the Data tab
Select Filter
Click on the dropdown menu and select the value or Condition you want displayed.

Conclusion

In conclusion, Microsoft Excel is such a powerful tool in data analysis. The magic that happens when different functions are entered in a cell and boom we have clean data, is one that needs it's own Magic show. Clean data, quality data for Analysis.

From a Local Folder to Github

Gloriah John — Sun, 23 Aug 2026 13:42:48 +0000

Introduction

Git is a tool used to track changes made to a Git repository, while GitHub is a platform where Git repositories are stored and shared publicly or privately. In this article I will explain the procedure from a local folder to GitHub using Git and an SSH key as learnt at LuxDevHq.

1. Creating a local Folder

On Git run,
mkdir First-GitHub-Project
'mkdir' is simply 'make directory'
Basically, we're telling the computer to make a folder called 'First GitHub Project'.
Next,
cd First-GitHub-Project
'cd' simply is 'Change directory'
We're basically moving into the folder created.

2. Creating a README File

A README file gives you the freedom to edit changes to the file created.
'touch README.md'
'touch' is used to create a new empty file with extensions such as '.md' or '.py'.

3. Configuring Our laptop

git --config global user.name 'Your username'
git --config global user.email 'Your email'

Configuration prepares our laptop for all the data work ahead.

4. Generate an SSH Key

An SSH key is a secure way for a laptop to connect to one's GitHub account without repeatedly using a password.
ssh-keygen -t ed25519 -C "your email"
An SSH key will be generated that you'll copy to your clipboard.

5. Connecting Github and Git

Open GitHub, Profile picture → Settings → SSH and GPG keys → New SSH key, give it a title, paste it in the box and save it.
Next,
We test our connection to
ssh -T git@github.com
If the connection is successful, a message of successful authentication will be displayed.

6. Connecting your Git project to GitHub

On Git, run the following commands consecutively:

git init to initialise a git repo
git status to check the repo
git add . to stage our file
git commit -m "write the commit message"
git log --oneline to display the commit message on one line
git branch to confirm if you are in the main branch
git branch -M main to change from master to main branch

Open Github and

Create a new repository
Go to the repository's quick setup and click on SSH
Copy the URL provide

Back on Git, run the following commands consecutively:

git remote add origin "paste the copied URL"
git remote -v
git push -u origin main
Enter a passphrase as prompted

Back to GitHub, refresh your page, and you'll be able to see the folder created displayed.

Conclusion

Coding is very interesting. The joy and thrill one feels when the Enter key is pressed and everything is running smoothly are incomparable. This data journey is an interesting one, and I'm looking forward to learning more and documenting the skills learnt in such articles.

DEV Community: Gloriah John

Getting Started with Excel : From Basics to Data Cleaning

Introduction

1. Excel Environment

Ribbon

Rows

Columns

Cells

Formula Bar

Quick Access Toolbar

Worksheet

2.Data Entry

3. Data Cleaning

Missing Values

Duplicate records

Spelling errors

Incorrect Data Types

Inconsistent Capitalization

Extra Spaces

4. Sorting and Filtering

Conclusion

From a Local Folder to Github

Introduction

1. Creating a local Folder

2. Creating a README File

3. Configuring Our laptop

4. Generate an SSH Key

5. Connecting Github and Git

6. Connecting your Git project to GitHub

Conclusion