在Pandas中通过创建列按组展平DataFrame

import pandas as pd

# 创建一个示例DataFrame
data = {'Group': ['A', 'A', 'B', 'B'],
        'Value': [1, 2, 3, 4]}
df = pd.DataFrame(data)

# 按照Group列进行分组，并展平DataFrame
def flatten_group(df_group):
    df_group = df_group.reset_index(drop=True)
    df_group = df_group.rename(columns={'Value': f'Value_{df_group["Group"].iloc[0]}'})
    return df_group

df_flattened = df.groupby('Group').apply(flatten_group).reset_index(drop=True)

print(df_flattened)

   Group  Value_A  Value_B
0      A        1      NaN
1      A        2      NaN
2      B      NaN        3
3      B      NaN        4