在Pandas中维护其他列的同时，将多列堆叠到单个列中？

import pandas as pd

# 创建一个示例DataFrame
data = {
    'ID': [1, 2, 3],
    'Name': ['Alice', 'Bob', 'Charlie'],
    'Score1': [85, 90, 78],
    'Score2': [88, 92, 80]
}
df = pd.DataFrame(data)

# 使用pd.melt()将多列堆叠到单个列中
stacked_df = pd.melt(df, id_vars=['ID', 'Name'], value_vars=['Score1', 'Score2'],
                      var_name='ScoreType', value_name='Score')

print(stacked_df)

   ID     Name ScoreType  Score
0   1    Alice    Score1     85
1   2      Bob    Score1     90
2   3  Charlie    Score1     78
3   1    Alice    Score2     88
4   2      Bob    Score2     92
5   3  Charlie    Score2     80

import pandas as pd

# 创建一个示例DataFrame
data = {
    'ID': [1, 2, 3],
    'Name': ['Alice', 'Bob', 'Charlie'],
    'Score1': [85, 90, 78],
    'Score2': [88, 92, 80]
}
df = pd.DataFrame(data)

# 使用DataFrame.stack()将多列堆叠到单个列中
stacked_df = df.set_index(['ID', 'Name']).stack().reset_index()
stacked_df.columns = ['ID', 'Name', 'ScoreType', 'Score']

print(stacked_df)

   ID     Name ScoreType  Score
0   1    Alice    Score1     85
1   1    Alice    Score2     88
2   2      Bob    Score1     90
3   2      Bob    Score2     92
4   3  Charlie    Score1     78
5   3  Charlie    Score2     80