An exhaustive list of dataviz libraries is maintained at https://github.com/fasouto/awesome-dataviz
For Python:
* altair - Declarative statistical visualizations, based on Vega-lite.
* bokeh - Interactive Web Plotting for Python.
* diagram - Text mode diagrams using UTF-8 characters
* ggplot - plotting system based on R's ggplot2.
* glumpy - OpenGL scientific visualizations library.
* holoviews - Complex and declarative visualizations from annotated data.
* matplotlib - 2D plotting library.
* missingno - provides flexible toolset of data-visualization utilities that allows quick visual summary of the completeness of your dataset, based on matplotlib.
* plotly - Interactive web based visualization built on top of plotly.js
* plotnine - A grammar of graphics for Python
* pygal - A dynamic SVG charting library.
* PyQtGraph - Interactive and realtime 2D/3D/Image plotting and science/engineering widgets.
* seaborn - A library for making attractive and informative statistical graphics.
* toyplot - The kid-sized plotting toolkit for Python with grownup-sized goals.
* Veusz - https://veusz.github.io
* VisPy - High-performance scientific visualization based on OpenGL.