你需要 import matplotlib.pyplot as plt 然后加上 plt.show() 在两个情节中的每一个之后。
修改后的代码添加如下：

import seaborn as sns
import pandas as pd
import matplotlib.pyplot as plt # Import Matplotlib
from pandas.api.types import CategoricalDtype

diamonds = sns.load_dataset("diamonds")

df=diamonds.copy()
cut_Kategoriler=["Fair","Good","Very Good","Premium","Ideal"]

df.cut=df.cut.astype(CategoricalDtype(categories = cut_Kategoriler,ordered=True))

print(df.head())

sns.catplot(x="cut",y="price",data=df)
plt.show() # Display the first plot
sns.barplot(x="cut",y="price",hue="color",data=df)
plt.show() # Display the second plot