Ploty (https://plot.ly/python/): This is a web-application-based toolkit for visualization. Its API for Jupyter Notebook and other applications makes it very powerful to represent 2D and 3D charts.

Ggplot (http://ggplot.yhathq.com/): This is a Python implementation based on the Grammar of Graphics library from the R programming language.

Altair (https://altair-viz.github.io/): This is built on the top of the powerful Vega-Lite visualization grammar and follows very declarative statistical visualization library techniques. In addition to that, it has a very descriptive and simple API.