python pandas:在行上按条件分组

import pandas as pd

data = {
    'Name': ['Alice', 'Bob', 'Charlie', 'David', 'Eva'],
    'Subject': ['Math', 'Math', 'Science', 'Science', 'Math'],
    'Score': [85, 90, 88, 78, 92]
}

df = pd.DataFrame(data)

grouped = df.groupby('Subject')['Score'].mean()
print(grouped)

grouped_multi = df.groupby(['Name', 'Subject'])['Score'].mean()
print(grouped_multi)

filtered_df = df[df['Score'] > 85]
grouped_condition = filtered_df.groupby('Subject')['Score'].mean()
print(grouped_condition)

# 删除包含NaN的分组键
df_clean = df.dropna(subset=['Subject'])

# 分组后重置索引
grouped_reset = df_clean.groupby('Subject')['Score'].mean().reset_index()
print(grouped_reset)