Sample data for exercises in Further Adventures in Data Cleaning.

Netflix is a popular streaming service that offers a vast catalog of movies, TV shows, and original contents. This dataset is a cleaned version of the original version which can be found here. The data consist of contents added to Netflix from 2008 to 2021. The oldest content is as old as 1925 and the newest as 2021. This dataset will be cleaned with PostgreSQL and visualized with Tableau. The purpose of this dataset is to test my data cleaning and visualization skills. The cleaned data can be found below and the Tableau dashboard can be found here .

Data Cleaning

We are going to: 1. Treat the Nulls 2. Treat the duplicates 3. Populate missing rows 4. Drop unneeded columns 5. Split columns Extra steps and more explanation on the process will be explained through the code comments

--View dataset

SELECT * 
FROM netflix;

--The show_id column is the unique id for the dataset, therefore we are going to check for duplicates
                                  
SELECT show_id, COUNT(*)                                                                                      
FROM netflix 
GROUP BY show_id                                                                                              
ORDER BY show_id DESC;

--No duplicates

--Check null values across columns

SELECT COUNT(*) FILTER (WHERE show_id IS NULL) AS showid_nulls,
    COUNT(*) FILTER (WHERE type IS NULL) AS type_nulls,
    COUNT(*) FILTER (WHERE title IS NULL) AS title_nulls,
    COUNT(*) FILTER (WHERE director IS NULL) AS director_nulls,
    COUNT(*) FILTER (WHERE movie_cast IS NULL) AS movie_cast_nulls,
    COUNT(*) FILTER (WHERE country IS NULL) AS country_nulls,
    COUNT(*) FILTER (WHERE date_added IS NULL) AS date_addes_nulls,
    COUNT(*) FILTER (WHERE release_year IS NULL) AS release_year_nulls,
    COUNT(*) FILTER (WHERE rating IS NULL) AS rating_nulls,
    COUNT(*) FILTER (WHERE duration IS NULL) AS duration_nulls,
    COUNT(*) FILTER (WHERE listed_in IS NULL) AS listed_in_nulls,
    COUNT(*) FILTER (WHERE description IS NULL) AS description_nulls
FROM netflix;

We can see that there are NULLS. 
director_nulls = 2634
movie_cast_nulls = 825
country_nulls = 831
date_added_nulls = 10
rating_nulls = 4
duration_nulls = 3 

The director column nulls is about 30% of the whole column, therefore I will not delete them. I will rather find another column to populate it. To populate the director column, we want to find out if there is relationship between movie_cast column and director column

-- Below, we find out if some directors are likely to work with particular cast

WITH cte AS
(
SELECT title, CONCAT(director, '---', movie_cast) AS director_cast 
FROM netflix
)

SELECT director_cast, COUNT(*) AS count
FROM cte
GROUP BY director_cast
HAVING COUNT(*) > 1
ORDER BY COUNT(*) DESC;

With this, we can now populate NULL rows in directors 
using their record with movie_cast 

UPDATE netflix 
SET director = 'Alastair Fothergill'
WHERE movie_cast = 'David Attenborough'
AND director IS NULL ;

--Repeat this step to populate the rest of the director nulls
--Populate the rest of the NULL in director as "Not Given"

UPDATE netflix 
SET director = 'Not Given'
WHERE director IS NULL;

--When I was doing this, I found a less complex and faster way to populate a column which I will use next

Just like the director column, I will not delete the nulls in country. Since the country column is related to director and movie, we are going to populate the country column with the director column

--Populate the country using the director column

SELECT COALESCE(nt.country,nt2.country) 
FROM netflix AS nt
JOIN netflix AS nt2 
ON nt.director = nt2.director 
AND nt.show_id <> nt2.show_id
WHERE nt.country IS NULL;
UPDATE netflix
SET country = nt2.country
FROM netflix AS nt2
WHERE netflix.director = nt2.director and netflix.show_id <> nt2.show_id 
AND netflix.country IS NULL;


--To confirm if there are still directors linked to country that refuse to update

SELECT director, country, date_added
FROM netflix
WHERE country IS NULL;

--Populate the rest of the NULL in director as "Not Given"

UPDATE netflix 
SET country = 'Not Given'
WHERE country IS NULL;

The date_added rows nulls is just 10 out of over 8000 rows, deleting them cannot affect our analysis or visualization

--Show date_added nulls

SELECT show_id, date_added
FROM netflix_clean
WHERE date_added IS NULL;

--DELETE nulls

DELETE F...

All data are prone to error and require data cleaning prior to analysis. An important example is longitudinal growth data, for which there are no universally agreed standard methods for identifying and removing implausible values and many existing methods have limitations that restrict their usage across different domains. A decision-making algorithm that modified or deleted growth measurements based on a combination of pre-defined cut-offs and logic rules was designed. Five data cleaning methods for growth were tested with and without the addition of the algorithm and applied to five different longitudinal growth datasets: four uncleaned canine weight or height datasets and one pre-cleaned human weight dataset with randomly simulated errors. Prior to the addition of the algorithm, data cleaning based on non-linear mixed effects models was the most effective in all datasets and had on average a minimum of 26.00% higher sensitivity and 0.12% higher specificity than other methods. Data cleaning methods using the algorithm had improved data preservation and were capable of correcting simulated errors according to the gold standard; returning a value to its original state prior to error simulation. The algorithm improved the performance of all data cleaning methods and increased the average sensitivity and specificity of the non-linear mixed effects model method by 7.68% and 0.42% respectively. Using non-linear mixed effects models combined with the algorithm to clean data allows individual growth trajectories to vary from the population by using repeated longitudinal measurements, identifies consecutive errors or those within the first data entry, avoids the requirement for a minimum number of data entries, preserves data where possible by correcting errors rather than deleting them and removes duplications intelligently. This algorithm is broadly applicable to data cleaning anthropometric data in different mammalian species and could be adapted for use in a range of other domains.

Dataset

This dataset was created by Deepali Sukhdeve

Contents

Dataset

This dataset was created by Martin Kanju

Released under Other (specified in description)

Contents

Clean Data Yolo_detection

## Overview

Clean Data Yolo_detection is a dataset for object detection tasks - it contains Objects annotations for 1,000 images.

## Getting Started

You can download this dataset for use within your own projects, or fork it into a workspace on Roboflow to create your own model.

  ## License

  This dataset is available under the [Public Domain license](https://creativecommons.org/licenses/Public Domain).

A subset of the Oregon Health Insurance Experiment (OHIE) contains 12,229 individuals who satisfied the inclusion criteria and who responded to the in-person survey by October 2010. It has been used to explore the heterogeneity of the effects of the lottery and the Insurance on a number of outcomes.

Dirty Retail Store Sales Dataset

Overview

The Dirty Retail Store Sales dataset contains 12,575 rows of synthetic data representing sales transactions from a retail store. The dataset includes eight product categories with 25 items per category, each having static prices. It is designed to simulate real-world sales data, including intentional "dirtiness" such as missing or inconsistent values. This dataset is suitable for practicing data cleaning, exploratory data analysis (EDA), and feature engineering.

File Information

• File Name: retail_store_sales.csv
• Number of Rows: 12,575
• Number of Columns: 11

Columns Description

Categories and Items

The dataset includes the following categories, each containing 25 items with corresponding codes, names, and static prices:

Electric Household Essentials

Furniture

Raw and clean data for Jyutping project, submitted to International Journal of Epidemiology.All data are openly available at the time of scrapping. I only retained Chinese Name and Hong Kong Government Romanised English Names. This project aims to describe the problem of non-standardised romanisation and it's impact on data linkage. The included data allows researchers to replicate my process of extracting Jyutping and Pinyin from Chinese Characters. Quite a few of manual screening and reviewing was required, so the code itself was not fully automated. The codes are stored on my personal GitHub, https://github.com/Jo-Lam/Jyutping_project/tree/main.Please cite this data resource: doi:10.5522/04/26504347

Raw labelled data used for analysis

This clean dataset is a refined version of our company datasets, consisting of 35M+ data records.

It’s an excellent data solution for companies with limited data engineering capabilities and those who want to reduce their time to value. You get filtered, cleaned, unified, and standardized B2B data. After cleaning, this data is also enriched by leveraging a carefully instructed large language model (LLM).

AI-powered data enrichment offers more accurate information in key data fields, such as company descriptions. It also produces over 20 additional data points that are very valuable to B2B businesses. Enhancing and highlighting the most important information in web data contributes to quicker time to value, making data processing much faster and easier.

For your convenience, you can choose from multiple data formats (Parquet, JSON, JSONL, or CSV) and select suitable delivery frequency (quarterly, monthly, or weekly).

Coresignal is a leading public business data provider in the web data sphere with an extensive focus on firmographic data and public employee profiles. More than 3B data records in different categories enable companies to build data-driven products and generate actionable insights. Coresignal is exceptional in terms of data freshness, with 890M+ records updated monthly for unprecedented accuracy and relevance.

Condensation Nuclei (CN) data collected by the University of Hawaii group (Clarke) in ACE1. All of the variables are average values for 15 second intervals. This dataset is a composite of all of the clean data files.

toufiqmusah/location-detection-clean-data dataset hosted on Hugging Face and contributed by the HF Datasets community

Dirty Cafe Sales Dataset

Overview

The Dirty Cafe Sales dataset contains 10,000 rows of synthetic data representing sales transactions in a cafe. This dataset is intentionally "dirty," with missing values, inconsistent data, and errors introduced to provide a realistic scenario for data cleaning and exploratory data analysis (EDA). It can be used to practice cleaning techniques, data wrangling, and feature engineering.

File Information

• File Name: dirty_cafe_sales.csv
• Number of Rows: 10,000
• Number of Columns: 8

Columns Description

Data Characteristics

1. Missing Values:

   • Some columns (e.g., Item, Payment Method, Location) may contain missing values represented as None or empty cells.

2. Invalid Values:

   • Some rows contain invalid entries like "ERROR" or "UNKNOWN" to simulate real-world data issues.

3. Price Consistency:

   • Prices for menu items are consistent but may have missing or incorrect values introduced.

Menu Items

The dataset includes the following menu items with their respective price ranges:

Use Cases

This dataset is suitable for: - Practicing data cleaning techniques such as handling missing values, removing duplicates, and correcting invalid entries. - Exploring EDA techniques like visualizations and summary statistics. - Performing feature engineering for machine learning workflows.

Cleaning Steps Suggestions

To clean this dataset, consider the following steps: 1. Handle Missing Values: - Fill missing numeric values with the median or mean. - Replace missing categorical values with the mode or "Unknown."

1. Handle Invalid Values:

   • Replace invalid entries like "ERROR" and "UNKNOWN" with NaN or appropriate values.

2. Date Consistency:

   • Ensure all dates are in a consistent format.
   • Fill missing dates with plausible values based on nearby records.

3. Feature Engineering:

   • Create new columns, such as Day of the Week or Transaction Month, for further analysis.

License

This dataset is released under the CC BY-SA 4.0 License. You are free to use, share, and adapt it, provided you give appropriate credit.

Feedback

If you have any questions or feedback, feel free to reach out through the dataset's discussion board on Kaggle.

taufiqsyed/salami-processed-enriched-clean-data-trunc dataset hosted on Hugging Face and contributed by the HF Datasets community

This is the cleaned household location data for the reproducible HHLocation case study

Dataset (Stata v15.1) containing responses from a survey of UK Clinical Research Collaboration registered clinical trial units (CTUs) and industry statisticians from both pharmaceuticals and clinical research organisations (http://dx.doi. org/10.1136/bmjopen-2020- 036875) Data is de-identified. The dataset contains descriptive variables describing participant's experience, as well as responses to questions on current adverse event analysis practices, awareness of specialist methods for adverse event analysis and priorities, concerns and barriers participants experience when analysing adverse event data.

E-commerce Product Dataset - Clean and Enhance Your Data Analysis Skills or Check Out The Cleaned File Below!

This dataset offers a comprehensive collection of product information from an e-commerce store, spread across 20+ CSV files and encompassing over 80,000+ products. It presents a valuable opportunity to test and refine your data cleaning and wrangling skills.

What's Included:

A variety of product categories, including:

• Apparel & Accessories
• Electronics
• Home & Kitchen
• Beauty & Health
• Toys & Games
• Men's Clothes
• Women's Clothes
• Pet Supplies
• Sports & Outdoor
• (and more!)

Each product record contains details such as:

• Product Title
• Category
• Price
• Discount information
• (and other attributes)

Challenges and Opportunities:

Data Cleaning: The dataset is "dirty," containing missing values, inconsistencies in formatting, and potential errors. This provides a chance to practice your data-cleaning techniques such as:

• Identifying and handling missing values
• Standardizing data formats
• Correcting inconsistencies
• Dealing with duplicate entries

Feature Engineering: After cleaning, you can explore opportunities to create new features from the existing data, such as: - Extracting keywords from product titles and descriptions - Deriving price categories - Calculating average discounts

Who can benefit from this dataset?

• Data analysts and scientists looking to practice data cleaning and wrangling skills on a real-world e-commerce dataset
• Machine learning enthusiasts interested in building models for product recommendation, price prediction, or other e-commerce tasks
• Anyone interested in exploring and understanding the structure and organization of product data in an e-commerce setting
• By contributing to this dataset and sharing your cleaning and feature engineering approaches, you can help create a valuable resource for the Kaggle community!

Mauritania Imports from Spain of Dish Washing Machines, Machinery for Cleaning was US$459.97 Thousand during 2024, according to the United Nations COMTRADE database on international trade. Mauritania Imports from Spain of Dish Washing Machines, Machinery for Cleaning - data, historical chart and statistics - was last updated on November of 2025.

Mexico Imports from Italy of Dish Washing Machines, Machinery for Cleaning was US$314.87 Million during 2024, according to the United Nations COMTRADE database on international trade. Mexico Imports from Italy of Dish Washing Machines, Machinery for Cleaning - data, historical chart and statistics - was last updated on December of 2025.