如何使用另一个数据框更新一个熊猫数据框(更新旧数据和添加新数据)

import pandas as pd

# 创建旧数据框
df_old = pd.DataFrame({'ID': [1, 2, 3],
                       'Name': ['Alice', 'Bob', 'Charlie'],
                       'Age': [25, 30, 35]})

# 创建新数据框
df_new = pd.DataFrame({'ID': [2, 3, 4],
                       'Name': ['Bob', 'Charlie', 'David'],
                       'Age': [32, 37, 40]})

# 使用merge()函数合并数据框
df_merged = pd.merge(df_old, df_new, on='ID', how='outer')

# 更新旧数据和添加新数据
df_merged['Name_x'].update(df_merged['Name_y'])
df_merged['Age_x'].update(df_merged['Age_y'])
df_merged.drop(['Name_y', 'Age_y'], axis=1, inplace=True)
df_merged.rename(columns={'Name_x': 'Name', 'Age_x': 'Age'}, inplace=True)

print(df_merged)

   ID     Name   Age
0   1    Alice  25.0
1   2      Bob  32.0
2   3  Charlie  37.0
3   4    David  40.0

import pandas as pd

# 创建旧数据框
df_old = pd.DataFrame({'ID': [1, 2, 3],
                       'Name': ['Alice', 'Bob', 'Charlie'],
                       'Age': [25, 30, 35]})

# 创建新数据框
df_new = pd.DataFrame({'ID': [2, 3, 4],
                       'Name': ['Bob', 'Charlie', 'David'],
                       'Age': [32, 37, 40]})

# 使用join()函数合并数据框
df_merged = df_old.set_index('ID').join(df_new.set_index('ID'), how='outer', lsuffix='_old', rsuffix='_new')

# 更新旧数据和添加新数据
df_merged['Name_old'].update(df_merged['Name_new'])
df_merged['Age_old'].update(df_merged['Age_new'])
df_merged.drop(['Name_new', 'Age_new'], axis=1, inplace=True)
df_merged.rename(columns={'Name_old': 'Name', 'Age_old': 'Age'}, inplace=True)

print(df_merged)

       Name   Age
ID               
1     Alice  25.0
2       Bob  32.0
3   Charlie  37.0
4     David  40.0