宽到长返回空输出- Python dataframe

import pandas as pd

# 创建一个示例DataFrame
data = {
    'id': [1, 2, 3],
    'name': ['Alice', 'Bob', 'Charlie'],
    'score_math': [90, 85, 95],
    'score_english': [80, 88, 92],
    'score_science': [95, 92, 88]
}

df = pd.DataFrame(data)

# 使用melt函数进行宽到长转换
df_long = pd.melt(df, id_vars=['id', 'name'], var_name='subject', value_name='score')

print(df_long)

   id     name         subject  score
0   1    Alice     score_math     90
1   2      Bob     score_math     85
2   3  Charlie     score_math     95
3   1    Alice  score_english     80
4   2      Bob  score_english     88
5   3  Charlie  score_english     92
6   1    Alice  score_science     95
7   2      Bob  score_science     92
8   3  Charlie  score_science     88