May 05, 2022 - 8 min read

Andrew Zahler

If you want to learn **in-demand skills**, consider data science and machine learning. These fields have become highly sought after in the job market given the increasing amount and importance of data in our world. And if you’re just getting into coding, the Python programming language provides a great entry point for beginners.

In this article, we’ll introduce you to the closely related fields of data science and machine learning. We’ll then explore Python’s dominance in these fields and get to know seven of the top Python libraries for working in them.

**We’ll cover**:

- Data science and machine learning: An overview
- 7 top Python libraries for data science and machine learning
- Wrapping up and next steps

Try one of our 300+ courses and learning paths: **An Introductory Guide to Data Science and Machine Learning**.

**Data science** is a field of applied mathematics and statistics that provides useful information based on the analysis and modeling of large amounts of data. **Machine learning** is a branch of artificial intelligence and computer science that involves developing computer systems that can learn and adapt using algorithms and statistical models. While these two fields sound unrelated, they’ve become inseparable in recent years. This is because while data science can gather insights, machine learning enables accurate and actionable predictions.

Data science and machine learning have become increasingly important in the era of **Big Data**, which is characterized by data sets too big and complex to be analyzed by humans or traditional data management systems. By using the tools of data science and machine learning, we can glean information from data to help make important decisions.

Today, **data modeling and analysis** are essential to the growth and success of businesses and organizations in **almost every sector**. You can find applications of data science and machine learning across areas as diverse as health care, road travel, sports, government, and e-commerce.

Some of the real-world applications of data science and machine learning include:

- Google has
**identified breast cancer tumors**that metastasize to nearby lymph nodes using a machine-learning tool called LYNA. The tool identified metastatic cancer with 99% accuracy using its algorithm, but more testing is needed before doctors can use it. - A company called StreetLight is
**modeling traffic patterns**for cars, bikes, and pedestrians in North America using data science and trillions of data points from smartphones and in-vehicle navigation devices. - UPS is
**optimizing package transportation**with a platform called Network Planning Tools that uses artificial intelligence and machine learning to work around bad weather and service bottlenecks. - RSPCT’s
**shooting-analysis system for basketball**transmits data from a sensor on the hoop’s rim to a device that displays shot details and generates predictive insights. The system has been adopted by NBA and college teams. - The IRS has improved its
**fraud detection**with taxpayer profiles built from public social media data, assorted metadata, emailing analysis, and electronic payment patterns. Based on those profiles, the IRS forecasts individual tax returns, and anyone whose returns diverge wildly gets flagged for auditing. (Privacy advocates have not been pleased.) - A company called Sovrn created
**intelligent advertising technology**compatible with Google and Amazon’s server-to-server bidding platforms to broker deals between advertisers and outlets.

Python is not the only language used in data science and machine learning. R is another dominant option, and Java, JavaScript, and C++ also have their places. But Python’s advantages have helped it earn its place as one of the most popular programming languages generally, and in data science and machine learning specifically.

These advantages include:

- Python is relatively
**easy to learn**. Its syntax is concise and resembles English, which helps make learning it more intuitive. - It has a large community of users. This translates into excellent
**peer support and documentation**. - Python is
**portable**and allows you to run its code anywhere. This means a Python application can run across Windows, MacOS, and Linux without modifications to its source code (unless there are system-specific calls). - Python is a
**free, open-source, and object-oriented**programming language. - Python makes it easy to
**add modules from other languages**, such as C and C++. - Finally, many of
**Python’s libraries**were literally made for data science and machine learning. We’ll talk more about this advantage in the next section.

In Python, a **library** is a collection of resources that contain pre-written code. As a programmer, this will save you time because you won’t have to write all your code from scratch. Python’s extensive collection of libraries enables all sorts of functionality, especially in data science and machine learning. Python has interactive libraries for data processing, data modeling, data manipulation, data visualization, machine learning algorithms, and more. Let’s talk about seven of the top Python libraries for these fields.

**NumPy** is a popular open-source library for data processing and modeling that is widely used in data science, machine learning, and deep learning. It’s also compatible with other libraries such as Pandas, Matplotlib, and Scikit-learn, which we’ll discuss later.

NumPy introduces objects for multidimensional arrays and matrices, along with routines that let you perform advanced mathematical and statistical functions on arrays with only a small amount of code. In addition, it contains some linear algebra functions and Fourier transforms.

**SciPy** is another open-source library for data processing and modeling that builds on NumPy for scientific computation applications. It contains more fully-featured versions of the linear algebra modules found in NumPy and many other numerical algorithms.

SciPy provides algorithms for optimization, integration, interpolation, eigenvalue problems, algebraic equations, differential equations, statistics, and other classes of problems.

It also adds a collection of algorithms and high-level commands for manipulating and visualizing data. For instance, by combining SciPy and NumPy, you can do things like image processing.

**Pandas** is an open-source package for data cleaning, processing, and manipulation. It provides extended, flexible data structures to hold different types of labeled and relational data.

Pandas specializes in manipulating numerical tables and time series, which are common data forms in data science.

Pandas is usually used along with other data science libraries: It’s built on NumPy, and it’s also used in SciPy for statistical analysis and Matplotlib for plotting functions.

**Matplotlib** is a data visualization and 2-D plotting library. In fact, it’s considered the most popular and widely used plotting library in the Python community.

Matplotlib stands out for its versatility. Matplotlib can be used in Python scripts, the Python and IPython shells, Jupyter notebooks, and web application servers. In addition, it offers a wide range of charts, including plots, bar charts, pie charts, histograms, scatterplots, error charts, power spectra, and stemplots.

**Seaborn** is a data visualization library based on Matplotlib and closely integrated with NumPy and Pandas data structures. It provides a high-level interface for creating statistical graphics that assist greatly with exploring and understanding data.

The data graphics available in Seaborn include bar charts, pie charts, histograms, scatterplots, and error charts.

**TensorFlow** is a popular machine learning platform developed by Google. Its use cases include natural language processing, image classification, creating neural networks, and more.

This platform provides a flexible “ecosystem” of libraries, tools, and user resources that are highly portable: You can train and deploy models anywhere, no matter what language or platform you use.

TensorFlow lets you build and train high-level machine-learning models using the Keras API, a feature of TensorFlow 2.0. It also provides eager execution, allowing for immediate iteration and easier debugging.

Note: Eager execution is an imperative programming environment that evaluates operations immediately, without needing to build graphs. This means operations return concrete values instead of constructing a computational graph to run later.

For bigger training tasks, TensorFlow provides the Distribution Strategy API, which lets you run training on different hardware configurations without changing your machine learning model.

**Scikit-learn**, also called sklearn, is a library for learning, improving, and executing machine learning models. It builds on NumPy and SciPy by adding a set of algorithms for common machine-learning and data-mining tasks.

Sklearn is the most popular Python library for performing classification, regression, and clustering algorithms. It’s considered a very curated library because developers don’t have to choose between different versions of the same algorithm.

Today we’ve given you a brief overview of data science and machine learning through the lens of Python and its top libraries for these fields. Hopefully, our discussion has piqued your interest and you’re considering learning more! We’ve just begun to scrape the surface of what you can do with Python’s libraries for data science and machine learning. There are many other libraries and packages worth exploring, like **Scrapy** and **BeautifulSoup** for web scraping and **Bokeh** for data visualization.

Whether you’re just learning to code or have some Python under your belt, we’ve created the course An Introductory Guide to Data Science and Machine Learning. This course is one of our many data science and machine learning resources, so be sure to check out our other offerings as you progress in your journey.

*Happy learning!*

WRITTEN BYAndrew Zahler

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