This webmap demonstates the result of using the geoplot and mplleaflet Python libraries to generate a simple HTML webmap. It was created with the following code:

# Load the data (uses the `quilt` package).
import geopandas as gpd
from quilt.data.ResidentMario import geoplot_data

troop_movements = gpd.read_file(geoplot_data.napoleon_troop_movements())
troop_movements['from'] = troop_movements.geometry.map(lambda v: v[0])
troop_movements['to'] = troop_movements.geometry.map(lambda v: v[1])


# Plot the data. We'll use a custom colormap, to match Minard's.
import geoplot as gplt
import matplotlib.pyplot as plt
import mplleaflet

from matplotlib.colors import LinearSegmentedColormap
colors = [(215/255, 193/255, 126/255), (37/255, 37/255, 37/255)]
cm = LinearSegmentedColormap.from_list('minard', colors)


gplt.sankey(troop_movements, start='from', end='to',
            scale='survivors', limits=(0.5, 45),
            hue='direction', categorical=True, cmap=cm)
fig = plt.gcf()
mplleaflet.save_html(fig, fileobj='minard-napoleon-russia.html')

The visualization chosen here is Minard's famous visualization on Napoleon's lethal march to Moscow and back <https://en.wikipedia.org/wiki/Charles_Joseph_Minard#Work>_. Compare with the original: