sns.stripplot设置legend=False报错，求移除或调整图例方案

我使用Seaborn的stripplot和pointplot绘制数据，代码如下：

sns.set_palette("Purples")

sns.stripplot(
    data=df_d_pt, x="feat", y="acc", hue="alpha",
    dodge=True, alpha=.2, legend=False,
)

sns.pointplot(
    data=df_d_pt, x="feat", y="acc", hue="alpha",
    dodge=.4, linestyle="none", errorbar=None,
    marker="_", markersize=10, markeredgewidth=3,
)

设置legend=False后触发报错，错误信息如下：

---------------------------------------------------------------------------
AttributeError
Traceback (most recent call last) <ipython-input-156-18efd4be2baa> in <module>
      3 sns.stripplot(
      4     data=df_d_pt, x="feat", y="acc", hue="alpha",
----> 5     dodge=True, alpha=.2, legend=False,
      6 )
      7 

~/.local/lib/python3.6/site-packages/seaborn/_decorators.py in inner_f(*args, **kwargs)
     44             )
     45         kwargs.update({k: arg for k, arg in zip(sig.parameters, args)})
---> 46         return f(**kwargs)
     47     return inner_f
     48 

~/.local/lib/python3.6/site-packages/seaborn/categorical.py in stripplot(x, y, hue, data, order, hue_order, jitter, dodge, orient, color, palette, size, edgecolor, linewidth, ax, **kwargs)    2820      linewidth=linewidth))    2821 
-> 2822     plotter.plot(ax, kwargs)    2823     return ax    2824 

~/.local/lib/python3.6/site-packages/seaborn/categorical.py in plot(self, ax, kws)    1158     def plot(self, ax, kws):    1159       """Make the plot."""
-> 1160         self.draw_stripplot(ax, kws)    1161         self.add_legend_data(ax)    1162         self.annotate_axes(ax)

~/.local/lib/python3.6/site-packages/seaborn/categorical.py in draw_stripplot(self, ax, kws)    1152                     kws.update(c=palette[point_colors])    1153                     if self.orient == "v":
-> 1154                         ax.scatter(cat_pos, strip_data, **kws)    1155                     else:    1156                         ax.scatter(strip_data, cat_pos, **kws)

/opt/conda/lib/python3.6/site-packages/matplotlib/__init__.py in inner(ax, data, *args, **kwargs)    1445     def inner(ax, *args, data=None, **kwargs):    1446         if data is None:
-> 1447             return func(ax, *map(sanitize_sequence, args), **kwargs)    1448     1449         bound = new_sig.bind(ax, *args, **kwargs)

/opt/conda/lib/python3.6/site-packages/matplotlib/cbook/deprecation.py in wrapper(*inner_args, **inner_kwargs)
    409                          else deprecation_addendum,
    410                 **kwargs)
-> 411         return func(*inner_args, **inner_kwargs)
    412 
    413     return wrapper

/opt/conda/lib/python3.6/site-packages/matplotlib/axes/_axes.py in scatter(self, x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, verts, edgecolors, plotnonfinite, **kwargs)    4496        )    4497         collection.set_transform(mtransforms.IdentityTransform())
-> 4498         collection.update(kwargs)    4499     4500         if colors is None:

/opt/conda/lib/python3.6/site-packages/matplotlib/artist.py in update(self, props)
    994                     func = getattr(self, f"set_{k}", None)
    995                     if not callable(func):
-> 996                         raise AttributeError(f"{type(self).__name__!r} object "
    997                                              f"has no property {k!r}")
    998                     ret.append(func(v))

AttributeError: 'PathCollection' object has no property 'legend'

移除legend=False后，图例位置不符合需求（图例覆盖图表内容），需要实现移除图例或将图例移到图表右侧的效果。

报错原因 #

stripplot函数本身不支持legend参数，传入的legend=False会被当作额外参数传递给底层Matplotlib的scatter方法，而scatter返回的PathCollection对象没有legend属性，因此触发AttributeError。

解决方案 #

方案1：移除图例

去掉stripplot中的legend=False，绘图完成后通过Matplotlib API移除图例：

import matplotlib.pyplot as plt
sns.set_palette("Purples")

sns.stripplot(
    data=df_d_pt, x="feat", y="acc", hue="alpha",
    dodge=True, alpha=.2
)

sns.pointplot(
    data=df_d_pt, x="feat", y="acc", hue="alpha",
    dodge=.4, linestyle="none", errorbar=None,
    marker="_", markersize=10, markeredgewidth=3,
)

# 方式1：清空图例内容
plt.legend([], [], frameon=False)

# 方式2：直接移除图例对象（更简洁）
# plt.gca().get_legend().remove()

方案2：将图例移到图表右侧

同样去掉stripplot中的legend=False，通过Matplotlib调整图例位置，避免覆盖图表：

import matplotlib.pyplot as plt
sns.set_palette("Purples")

sns.stripplot(
    data=df_d_pt, x="feat", y="acc", hue="alpha",
    dodge=True, alpha=.2
)

sns.pointplot(
    data=df_d_pt, x="feat", y="acc", hue="alpha",
    dodge=.4, linestyle="none", errorbar=None,
    marker="_", markersize=10, markeredgewidth=3,
)

# 将图例移到图表右侧，bbox_to_anchor参数避免覆盖图表
plt.legend(bbox_to_anchor=(1.05, 1), loc='upper left', borderaxespad=0)
# 调整布局防止图例被裁剪
plt.tight_layout()

内容的提问来源于stack exchange，提问作者Kadaj13