unable to plot with custom color ramp seaborn 0.12.0

I was trying to use seaborn kdeplot with custom colour ramp, it is working with seaboarn version 0.11.00, but not with seaboarn 0.12.0

color ramp as below

def make_Ramp( ramp_colors ): 
    from colour import Color
    from matplotlib.colors import LinearSegmentedColormap

    color_ramp = LinearSegmentedColormap.from_list( 'my_list', [ Color( c1 ).rgb for c1 in ramp_colors ] )
    plt.figure( figsize = (15,3))
    plt.imshow( [list(np.arange(0, len( ramp_colors ) , 0.1)) ] , interpolation='nearest', origin='lower', cmap= color_ramp )
    plt.xticks([])
    plt.yticks([])
    return color_ramp

custom_ramp = make_Ramp( ['#0000ff','#00ffff','#ffff00','#ff0000' ] ) 

my data look like this

            0        1         2
0    142.5705  38.5744  hairpins
1    281.0795  55.1900  hairpins
2    101.7282  49.5604  hairpins
3     59.8472  63.0699  hairpins
4    296.4381  44.8293  hairpins
..        ...      ...       ...
347  284.6841  51.7468     stems
348  288.7241  49.9322     stems
349  320.2972  41.5520     stems
350  302.6805  67.2658     stems
351  293.6837  52.0663     stems

[352 rows x 3 columns]
<class 'numpy.float64'>

this is my code

ax = sns.kdeplot(data=df, x=df.loc[df[2] == "hairpins", 0], y=df.loc[df[2] == "hairpins", 1], fill=False, thresh=0, levels=20, cmap=custom_ramp, common_norm=True, cbar=True, )

with version 0.12.0 get this error

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
[<ipython-input-6-88652c0ba7ce>](https://localhost:8080/#) in <module>
     21   #/
     22     plt.subplot(2,3,i+1)
---> 23     ax = sns.kdeplot(data=df, x=df.loc[df[2] == dimtypes[i], 0], y=df.loc[df[2] == dimtypes[i], 1], fill=False, thresh=0, levels=20, cmap=custom_ramp, common_norm=True, cbar=True, cbar_kws={'format': '%2.1e', 'label': 'kernel density'} )
     24     plt.title("Chart {}: {}".format(i+1, dimtypes[i]), size=20)
     25     plt.xlabel(str(xname), fontsize=12)

9 frames
[/usr/local/lib/python3.7/dist-packages/matplotlib/artist.py](https://localhost:8080/#) in update(self, props)
   1065                     func = getattr(self, f"set_{k}", None)
   1066                     if not callable(func):
-> 1067                         raise AttributeError(f"{type(self).__name__!r} object "
   1068                                              f"has no property {k!r}")
   1069                     ret.append(func(v))

AttributeError: 'Line2D' object has no property 'cmap'

with version 0.11.0 get this plot

basically, custom ramp is not woking with seaborn 0.12.0 , please update thanks

[mwaskom]

Thanks @y-h-wang, this is a perfect reprex and makes it much easier to debug. Indeed, this is a regression, not an intentional change. The root cause is https://github.com/mwaskom/seaborn/pull/2449.

[y-h-wang]

Encountered the same issue. The following code shows a reproducible example that works with seaborn 0.11.0 while ends up with AttributeError: 'Line2D' object has no property 'cmap' with 0.12.0. I would assume this is not a desired feature since nothing related mentioned in the changelog.

import numpy as np; np.random.seed(10)
import seaborn as sns; sns.set(color_codes=True)
import matplotlib.pyplot as plt

mean, cov = [0, 2], [(1, .5), (.5, 1)]
x, y = np.random.multivariate_normal(mean, cov, size=50).T
sns.kdeplot(x=x, y=y, cmap='Blues')
plt.show()