如何在python中按字母顺序使用颜色渐变的plot标签？

Question

我想 plot 标签“nutrition_grade_fr”在 python 中按字母顺序排列，颜色渐变。

这是我的图表的代码，但它没有按字母顺序显示标签，也没有显示相应的色调：

import seaborn as sns
import matplotlib.pyplot as plt 

df = nutri_app

for elem in ['energy_100g', 'sugars_100g','fat_100g','proteins_100g']:
#Create barplot
    fig, ax = plt.subplots(figsize=(30,6))
    sns.barplot(x="pnns_group1", y=elem, hue="nutrition_grade_fr", data=df)

#Add title
    ax.set_title(f"nutriscore by categories related to {elem} quantity variable")

#Show plot
    plt.show()

Answer 1

您需要pandas.DataFrame.sort_values并选择一个调色板（例如，蓝色）：

import seaborn as sns
import matplotlib.pyplot as plt 

df = nutri_app.sort_values(by='nutrition_grade_fr') #ascending=True by default

for elem in ['energy_100g', 'sugars_100g','fat_100g','proteins_100g']:
#Create barplot
    fig, ax = plt.subplots(figsize=(30,6))
    sns.barplot(x="pnns_group1", y=elem, hue="nutrition_grade_fr", data=df, palette='Blues')

#Add title
    ax.set_title(f"nutriscore by categories related to {elem} quantity variable")

#Show plot
plt.show();