How to change legend position in seaborn kdeplot?

Question

I try to change kdeplot legend position. unfortunelly position is changed but contents is not showing. outline only. My code is:

import pandas as pd
import seaborn as sns 
import matplotlib.pyplot as plt
df=pd.read_excel('mydata.xlsx',sheet_name=0)
ax=sns.kdeplot(data=df,x="c",hue="scan",shade=True,palette="deep",legend=False)
ax.legend(loc='upper left', bbox_to_anchor=(0.25, 0.75))
plt.show()

anboy help me~

Answer 1

For some strange reason, the current seaborn ( 0.11.0 ) and matplotlib ( 3.3.2 ) versions give an error No handles with labels found to put in legend .

But the following approach seems to work. Note that _set_loc(2) only accepts a code, not a string, where 2 corresponds to 'upper left' .

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

df = pd.DataFrame({"c": np.random.randn(10000).cumsum(),
                   "scan": np.repeat([*'abcd'], 2500)})
ax = sns.kdeplot(data=df, x="c", hue="scan", shade=True, palette="deep")
ax.legend_.set_bbox_to_anchor((0.05, 0.95))
ax.legend_._set_loc(2)
plt.show()

PS: Explicitly providing the legend labels also seems to work, but then probably hue_order is needed to ensure the order is the same.

scan_labels = np.unique(df['scan'])
ax = sns.kdeplot(data=df, x="c", hue="scan", hue_order=scan_labels, shade=True, palette="deep", legend=True)
ax.legend(labels=scan_labels, bbox_to_anchor=(0.05, 0.95), loc='upper left', title='scan')