Incorrect legend in lineplot when using numeric values in hue

I believe this is related to #1560 but happens even when style is not used and gives incorrect behaviour with lineplot.

Here’s an example. The legend should have two items, 0.2 and 0.3

import matplotlib.pyplot as plt
import seaborn as sns
import pandas as pd

df = pd.DataFrame(
    [
        [0, 0, .2],
        [1, 1, .2],
        [2, 2, .2],
        [0, 0.5, .3],
        [1, 1.5, .3],
        [2, 2.5, .3],
    ],
    columns=['x','y','hue']
)

sns.lineplot(data=df, x='x', y='y', hue='hue')
plt.show()

Interestingly it works if the hue column contains strings or integers as the categorical value rather than floats. I guess casting that column to a string could be a workaround in the meantime.

[arvoelke]

My current work-around is to convert the hue entries into strings that will not be reinterpreted as something else. e.g.,

df["hue"] = ["$%s$" % x for x in df["hue"]]

where the $...$ is a hack (with the side-effect of rendering the number in LaTeX) that prevents:

AttributeError: 'str' object has no attribute 'view'

Other schemes such as "= %s" % x also work.

[alunawat]

Just set legend=‘full’ in the call to seaborn lineplot