Também não conheço esses pacotes. Em Python um pacote bem legal é o Seaborn.
Com este pacote você consegue fazer de formas simples e rápida coisas que seriam bem mais complicadas de fazer no Matplotlib (dê uma olhada nos exemplos disponíveis).
Editando a resposta:
Encontrei mais alguns pacotes que parecem ser interessantes:
1) Lightning:
"Lightning is a framework for interactive data visualization, including a server, visualizations, and client libraries. The Lightning server provides API-based access to reproducible, web-based visualizations."
2) Holoviews:
"Composable, declarative data structures for building even complex visualizations easily. HoloViews is a Python library that makes analyzing and visualizing scientific or engineering data much simpler, more intuitive, and more reproducible."
3) Altair:
"This package exposes a Python API for building statistical visualizations in a declarative manner. This API contains no actual visualization rendering code, but instead just emits JSON data that follows the vega-lite specification. Actual plotting code is done by renderers that are provided by other plotting libraries."
O Altair parece bem legal para fins exploratórios.