Vincent Favour
6 min readJan 9, 2023


How to troubleshoot and debug data problems

Data is a crucial component of many business, scientific, and analytical endeavors, and ensuring that it is accurate, complete, and correctly formatted is essential for making informed decisions and deriving meaningful insights.

However, data problems can arise for a variety of reasons, ranging from simple mistakes to more complex issues such as system errors or data corruption.

In this post, we’ll explore some strategies for troubleshooting and debugging data problems, and provide examples of how to implement these techniques using Python (I use python 🐍 a lot 😁).

📊 Identifying the root cause of a data problem

The first step in solving a data problem is to identify what is causing the issue.

This can often be a challenging task, as data problems can have a range of causes and may not always be immediately apparent.

However, by breaking the problem down into smaller pieces and systematically testing and eliminating possible causes, it is usually possible to identify the root cause of the issue.

One effective way to approach this process is to use data visualization and SQL queries to analyze the data and identify any patterns or anomalies that may indicate a problem.

For example,

let's say we have a dataset containing customer purchase data, and we suspect that there may be some errors in the product names.

We could use a bar chart to visualize the distribution of product names and see if there are any unusual or unexpected values:

By inspecting the chart, we might be able to identify any product names that are clearly incorrect or out of place.

We could then use a SQL query to further investigate these values and determine whether they are the result of data entry errors, system errors, or some other issue:

By combining visualization and SQL queries, we can often quickly zero in on the source of a data problem and begin to formulate a plan for resolving it.

🧑‍💻 Debugging and fixing formatting errors in data

Formatting errors are another common type of data problem that can occur when data is imported or entered into a system.

These errors can take many forms, such as incorrect data types, inconsistent formatting, or invalid values.

If left unchecked, formatting errors can lead to downstream issues and cause problems with data analysis and decision-making.

To fix formatting errors, it is often necessary to first identify and locate the problematic values.

One approach to doing this is to use built-in functions and methods in Python to detect and correct formatting errors.

For example

If we have a dataset containing dates that are formatted in different ways, we can use the pd.to_datetime() function to convert them all to a consistent format:

We can also use the .apply() method to apply a custom function to a column in our data to correct formatting errors.

For example

Let’s say we have a dataset containing customer names, and some of the names are capitalized differently from others. We can use the following code to standardize the capitalization of all the names:

By using these and similar techniques, it is often possible to quickly and effectively fix formatting errors in data.

💡 Handling missing or incomplete data

Missing or incomplete data is another common problem that can arise in the course of working with data.

This can occur for a variety of reasons, such as data entry errors, system failures, or simply the fact that some data is not available for certain records.

Regardless of the cause, missing or incomplete data can be a significant issue, as it can lead to incomplete or incorrect analysis and decision-making.

There are a few different strategies that can be used to address missing or incomplete data.

  • One option is to simply drop rows or columns that contain missing values. This can be done using the pd.dropna() function in pandas:

Another option is to impute missing values, which involves replacing missing values with estimates based on the available data.

There are several ways to perform imputation, such as using the mean or median of the available values, or using machine learning algorithms to predict the missing values based on the other data in the dataset.

Here is an example of using the .fillna() method to impute missing values with the mean of the available data:

👏 Ensuring data integrity and consistency

Once we have addressed any immediate data problems, it is important to take steps to ensure that the data remains clean and accurate over time.

This can involve implementing regular checks and audits to identify and fix any new issues that may arise, as well as establishing processes and protocols for handling data to minimize the risk of errors.

One simple technique for maintaining data integrity is

  1. Use the .unique() method to identify unique values in the "ProductName" column
  2. Use the .value_counts() method to count the number of occurrences of each value

By regularly verifying the integrity of our data in this way, we can help to ensure that it remains accurate and useful for analysis and decision-making.

〽️ Tips and tricks for efficient data troubleshooting and debugging

Troubleshooting and debugging data problems can be a time-consuming and frustrating task, but there are a few strategies and techniques that can help to streamline the process and make it more efficient.

Some tips and tricks to consider include:

  1. Use version control to track changes to your data and make it easier to undo mistakes or revert to earlier versions if necessary. Tools like git are widely used for this purpose and can make it much easier to manage and maintain data over time.
  2. Test changes before implementing them on your entire dataset. This can help to ensure that you are not inadvertently introducing new problems or breaking existing functionality.
  3. Document and track data problems and their resolutions. This can behelp to ensure that similar issues can be addressed more efficiently in the future.
  4. Seek out resources and learning opportunities to expand your knowledge and skills in data troubleshooting and debugging. There are many books, courses, and online resources (just like this) that can help you to become more proficient in this area.


In this post, we have explored some strategies for troubleshooting and debugging data problems, and provided examples of how to implement these techniques using Python.

By following these best practices and using the tools and resources at our disposal, we can ensure that our data is accurate and reliable, and that it supports informed decision-making and meaningful insights.

Thank you for reading this post on how to troubleshoot and debug data problems.

I hope that you have found it helpful and that you have learned some new techniques and strategies for identifying and resolving data issues.

If you have any questions or comments, please don’t hesitate to reach out.

Good luck with your data troubleshooting and debugging endeavors! 🧑‍💻



Vincent Favour

Talks about Programming, Data science, Inspiration quotes and Academic Affairs. Reach me on twitter : @ogboifavour