10 Lesser-Known Python Libraries Every Data Scientist Should Be Using in 2026

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# Introduction

 
As a data scientist, you're probably already familiar with libraries like NumPy, pandas, scikit-learn, and Matplotlib. But the Python ecosystem is vast, and there are plenty of lesser-known libraries that can help you make your data science tasks easier.

In this article, we'll explore ten such libraries organized into four key areas that data scientists work with daily:

• Automated EDA and profiling for faster exploratory analysis
• Large-scale data processing for handling datasets that don't fit in memory
• Data quality and validation for maintaining clean, reliable pipelines
• Specialized data analysis for domain-specific tasks like geospatial and time series work

We’ll also give you learning resources that’ll help you hit the ground running. I hope you find a few libraries to add to your data science toolkit!

# 1. Pandera

 
Data validation is essential in any data science pipeline, yet it's often done manually or with custom scripts. Pandera is a statistical data validation library that brings type-hinting and schema validation to pandas DataFrames.

Here's a list of features that make Pandera useful:

• Allows you to define schemas for your DataFrames, specifying expected data types, value ranges, and statistical properties for each column
• Integrates with pandas and provides informative error messages when validation fails, making debugging much easier.
• Supports hypothesis testing within your schema definitions, letting you validate statistical properties of your data during pipeline execution.

How to Use Pandas With Pandera to Validate Your Data in Python by Arjan Codes provides clear examples for getting started with schema definitions and validation patterns.

# 2. Vaex

 
Working with datasets that don't fit in memory is a common challenge. Vaex is a high-performance Python library for lazy, out-of-core DataFrames that can handle billions of rows on a laptop.

Key features that make Vaex worth exploring:

• Uses memory mapping and lazy evaluation to work with datasets larger than RAM without loading everything into memory
• Provides fast aggregations and filtering operations by leveraging efficient C++ implementations
• Offers a familiar pandas-like API, making the transition smooth for existing pandas users who need to scale up

Vaex introduction in 11 minutes is a quick introduction to working with large datasets using Vaex.

# 3. Pyjanitor

 
Data cleaning code can become messy and hard to read quickly. Pyjanitor is a library that provides a clean, method-chaining API for pandas DataFrames. This makes data cleaning workflows more readable and maintainable.

Here's what Pyjanitor offers:

• Extends pandas with additional methods for common cleaning tasks like removing empty columns, renaming columns to snake_case, and handling missing values.
• Enables method chaining for data cleaning operations, making your preprocessing steps read like a clear pipeline
• Includes functions for common but tedious tasks like flagging missing values, filtering by time ranges, and conditional column creation

Watch Pyjanitor: Clean APIs for Cleaning Data talk by Eric Ma and check out Easy Data Cleaning in Python with PyJanitor – Full Step-by-Step Tutorial to get started.

# 4. D-Tale

 
Exploring and visualizing DataFrames often requires switching between multiple tools and writing lots of code. D-Tale is a Python library that provides an interactive GUI for visualizing and analyzing pandas DataFrames with a spreadsheet-like interface.

Here's what makes D-Tale useful:

• Launches an interactive web interface where you can sort, filter, and explore your DataFrame without writing additional code
• Provides built-in charting capabilities including histograms, correlations, and custom plots accessible through a point-and-click interface
• Includes features like data cleaning, outlier detection, code export, and the ability to build custom columns through the GUI

How to quickly explore data in Python using the D-Tale library provides a comprehensive walkthrough.

# 5. Sweetviz

 
Generating comparative analysis reports between datasets is tedious with standard EDA tools. Sweetviz is an automated EDA library that creates useful visualizations and provides detailed comparisons between datasets.

What makes Sweetviz useful:

• Generates comprehensive HTML reports with target analysis, showing how features relate to your target variable for classification or regression tasks
• Great for dataset comparison, allowing you to compare training vs test sets or before vs after transformations with side-by-side visualizations
• Produces reports in seconds and includes association analysis, showing correlations and relationships between all features

How to Quickly Perform Exploratory Data Analysis (EDA) in Python using Sweetviz tutorial is a great resource to get started.

# 6. cuDF

 
When working with large datasets, CPU-based processing can become a bottleneck. cuDF is a GPU DataFrame library from NVIDIA that provides a pandas-like API but runs operations on GPUs for massive speedups.

Features that make cuDF helpful:

• Provides 50-100x speedups for common operations like groupby, join, and filtering on compatible hardware
• Offers an API that closely mirrors pandas, requiring minimal code changes to leverage GPU acceleration
• Integrates with the broader RAPIDS ecosystem for end-to-end GPU-accelerated data science workflows

NVIDIA RAPIDS cuDF Pandas - Large Data Preprocessing with cuDF pandas accelerator mode by Krish Naik is a useful resource to get started.

# 7. ITables

 
Exploring DataFrames in Jupyter notebooks can be clunky with large datasets. ITables (Interactive Tables)brings interactive DataTables to Jupyter, allowing you to search, sort, and paginate through your DataFrames directly in your notebook.

What makes ITables helpful:

• Converts pandas DataFrames into interactive tables with built-in search, sorting, and pagination functionality
• Handles large DataFrames efficiently by rendering only visible rows, keeping your notebooks responsive
• Requires minimal code; often just a single import statement to transform all DataFrame displays in your notebook.

Quick Start to Interactive Tables includes clear usage examples.

# 8. GeoPandas

 
Spatial data analysis is increasingly important across industries. Yet many data scientists avoid it due to complexity. GeoPandas extends pandas to support spatial operations, making geographic data analysis accessible.

Here's what GeoPandas offers:

• Provides spatial operations like intersections, unions, and buffers using a familiar pandas-like interface
• Handles various geospatial data formats including shapefiles, GeoJSON, and PostGIS databases
• Integrates with matplotlib and other visualization libraries for creating maps and spatial visualizations

Geospatial Analysis micro-course from Kaggle covers GeoPandas basics.

# 9. tsfresh

 
Extracting meaningful features from time series data manually is time-consuming and requires domain expertise. tsfresh automatically extracts hundreds of time series features and selects the most relevant ones for your prediction task.

Features that make tsfresh useful:

• Calculates time series features automatically, including statistical properties, frequency domain features, and entropy measures
• Includes feature selection methods that identify which features are actually relevant for your specific prediction task

Introduction to tsfresh covers what tsfresh is and how it’s useful in time series feature engineering applications.

# 10. ydata-profiling (pandas-profiling)

 
Exploratory data analysis can be repetitive and time-consuming. ydata-profiling (formerly pandas-profiling) generates comprehensive HTML reports for your DataFrame with statistics, correlations, missing values, and distributions in seconds.

What makes ydata-profiling useful:

• Creates extensive EDA reports automatically, including univariate analysis, correlations, interactions, and missing data patterns
• Identifies potential data quality issues like high cardinality, skewness, and duplicate rows
• Provides an interactive HTML report that you can share wittsfresh stakeholders or use for documentation

Pandas Profiling (ydata-profiling) in Python: A Guide for Beginners from DataCamp includes detailed examples.

# Wrapping Up

 
These ten libraries address real challenges you'll face in data science work. To summarize, we covered useful libraries to work with datasets too large for memory, need to quickly profile new data, want to ensure data quality in production pipelines, or work with specialized formats like geospatial or time series data.

You don't need to learn all of these at once. Start by identifying which category addresses your current bottleneck.

• If you spend too much time on manual EDA, try Sweetviz or ydata-profiling.
• If memory is your constraint, experiment with Vaex.
• If data quality issues keep breaking your pipelines, look into Pandera.

Happy exploring!
 
 

Bala Priya C is a developer and technical writer from India. She likes working at the intersection of math, programming, data science, and content creation. Her areas of interest and expertise include DevOps, data science, and natural language processing. She enjoys reading, writing, coding, and coffee! Currently, she's working on learning and sharing her knowledge with the developer community by authoring tutorials, how-to guides, opinion pieces, and more. Bala also creates engaging resource overviews and coding tutorials.