NumPy is the fundamental open-source Python library for numerical computing. It provides multidimensional arrays and fast functions for linear algebra, statistics and random numbers, with its core running in compiled code. Many data analysis and machine learning tools, such as pandas, scikit-learn and numerous visualisation libraries, are built on NumPy. Anyone working with data in Python therefore almost always uses it, directly or indirectly.
pandas is an open-source Python library for analysing and manipulating tabular data, developed from 2008 onwards by Wes McKinney. Its central object, the DataFrame, resembles a table with named columns. It can be used to load data from CSV files, Excel or databases and to clean, filter, group and merge it. pandas is built on NumPy and is a standard tool in data analysis, reporting and training data preparation.
Scikit-learn is an open-source Python library for classical machine learning. It provides consistent tools for classification, regression, clustering, dimensionality reduction, data preprocessing and model evaluation, such as cross-validation. Built on NumPy and SciPy, it is widely used in education, research and practice thanks to its simple, uniform interface. For deep neural networks, frameworks such as PyTorch or TensorFlow are usually chosen instead.
Jupyter Notebook is an open-source, browser-based application from Project Jupyter that combines executable code, results, charts and explanatory text in a single document. Notebooks are widely used in data analysis, machine learning, research and teaching because each step can be documented and shared in a traceable way. Python is the most common language. Example: an analyst loads sales data, cleans it and shows the results as a chart directly below.
TensorFlow is an open-source machine learning framework developed by Google and released in 2015. It is used to build, train and deploy neural networks in applications, on servers or on mobile devices. Keras provides an accessible high-level interface; typical uses include image classification, forecasting and recommendation systems.
