import seaborn as sns
import matplotlib.pyplot as plt
# Load example dataset
iris = sns.load_dataset("iris")
# Define marker styles "Circle", "Square", "Diamond"
marker_styles = ['o', 's', 'D']  
# Map species to marker styles  (read again as  "Circle", "Square", "Diamond")
species_to_marker = {'setosa': 'o', 'versicolor': 's', 'virginica': 'D'}
iris['markers'] = iris['species'].map(species_to_marker)
# Pass marker style column to scatterplot arguments
# This sort of works:  at least maps the variable to the default marker style:
scatter_kws = {'s': 100, 'alpha': 0.5, 'style': iris['species']}  # 'style' assigns DEFAULT markers which can be interpreted as "circle, x, square"  
# This doesn't work: I want to use my non-default markers that are mapped to the variable:
# scatter_kws = {'s': 100, 'alpha': 0.5, 'style': iris['species'], 'marker': iris['markers']}  # I want to overwrite marker-style with my custom defined marker_styles now mapped in variable iris['markers']
# Pass scatterplot arguments to pairplot, only plot lower-left-triangle of pairs
sns.pairplot(iris, vars=["sepal_width", "petal_length", "petal_width"],
             hue="species", diag_kind="kde", plot_kws=scatter_kws, corner=True)
# Display the plot
plt.show()

scatter_kws = {'s': 100, 'alpha': 0.5, 'style': iris['species'], 'marker': iris['markers']}

TypeError                                 Traceback (most recent call last)
<ipython-input-600-3640788f836b> in <cell line: 21>()
     19 
     20 # Pass scatterplot arguments to pairplot
---> 21 sns.pairplot(iris, vars=["sepal_width", "petal_length", "petal_width"],
     22              hue="species", diag_kind="kde", plot_kws=scatter_kws, corner=True)
     23 
8 frames
/usr/local/lib/python3.10/dist-packages/seaborn/axisgrid.py in pairplot(data, hue, hue_order, palette, vars, x_vars, y_vars, kind, diag_kind, markers, height, aspect, corner, dropna, plot_kws, diag_kws, grid_kws, size)
   2156     if kind == "scatter":
   2157         from .relational import scatterplot  # Avoid circular import
-> 2158         plotter(scatterplot, **plot_kws)
   2159     elif kind == "reg":
   2160         from .regression import regplot  # Avoid circular import
/usr/local/lib/python3.10/dist-packages/seaborn/axisgrid.py in map_offdiag(self, func, **kwargs)
   1417         """
   1418         if self.square_grid:
-> 1419             self.map_lower(func, **kwargs)
   1420             if not self._corner:
   1421                 self.map_upper(func, **kwargs)
/usr/local/lib/python3.10/dist-packages/seaborn/axisgrid.py in map_lower(self, func, **kwargs)
   1387         """
   1388         indices = zip(*np.tril_indices_from(self.axes, -1))
-> 1389         self._map_bivariate(func, indices, **kwargs)
   1390         return self
   1391 
/usr/local/lib/python3.10/dist-packages/seaborn/axisgrid.py in _map_bivariate(self, func, indices, **kwargs)
   1566             if ax is None:  # i.e. we are in corner mode
   1567                 continue
-> 1568             self._plot_bivariate(x_var, y_var, ax, func, **kws)
   1569         self._add_axis_labels()
   1570 
/usr/local/lib/python3.10/dist-packages/seaborn/axisgrid.py in _plot_bivariate(self, x_var, y_var, ax, func, **kwargs)
   1607                 "hue": hue, "hue_order": self._hue_order, "palette": self._orig_palette,
   1608             })
-> 1609         func(x=x, y=y, **kwargs)
   1610 
   1611         self._update_legend_data(ax)
/usr/local/lib/python3.10/dist-packages/seaborn/relational.py in scatterplot(data, x, y, hue, size, style, palette, hue_order, hue_norm, sizes, size_order, size_norm, markers, style_order, legend, ax, **kwargs)
    759     kwargs["color"] = _default_color(ax.scatter, hue, color, kwargs)
    760 
--> 761     p.plot(ax, kwargs)
    762 
    763     return ax
/usr/local/lib/python3.10/dist-packages/seaborn/relational.py in plot(self, ax, kws)
    566         if not isinstance(m, mpl.markers.MarkerStyle):
    567             # TODO in more recent matplotlib (which?) can pass a MarkerStyle here
--> 568             m = mpl.markers.MarkerStyle(m)
    569         if m.is_filled():
    570             kws.setdefault("edgecolor", "w")
/usr/local/lib/python3.10/dist-packages/matplotlib/markers.py in __init__(self, marker, fillstyle, transform, capstyle, joinstyle)
    270                 "%(since)s; support will be removed %(removal)s.  Use "
    271                 "MarkerStyle('') to construct an empty MarkerStyle.")
--> 272         self._set_marker(marker)
    273 
    274     __init__.__signature__ = inspect.signature(  # Only for deprecation period.
/usr/local/lib/python3.10/dist-packages/matplotlib/markers.py in _set_marker(self, marker)
    349             self._marker_function = self._set_tuple_marker
    350         elif (not isinstance(marker, (np.ndarray, list)) and
--> 351               marker in self.markers):
    352             self._marker_function = getattr(
    353                 self, '_set_' + self.markers[marker])
TypeError: unhashable type: 'Series'

scatter_kws = {'s': 100, 'alpha': 0.5, 'style': iris['species'], 'marker': iris['markers'].tolist()}

ValueError: Unrecognized marker style ['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 's', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D', 'D']