从pandas中具有不同值的列中获取唯一值，并根据条件将行拆分为多行

import pandas as pd

# 创建一个示例DataFrame
data = {'Name': ['John', 'Alice', 'Bob', 'Alice', 'John'],
        'Age': [25, 30, 35, 30, 25],
        'City': ['New York', 'Paris', 'London', 'Paris', 'New York']}
df = pd.DataFrame(data)

# 获取唯一的城市值
unique_cities = df['City'].unique()

# 根据条件将行拆分为多行
new_rows = []
for city in unique_cities:
    city_rows = df[df['City'] == city]
    for index, row in city_rows.iterrows():
        new_row = row.copy()
        new_row['City'] = city
        new_rows.append(new_row)

# 创建新的DataFrame
new_df = pd.DataFrame(new_rows)

# 打印结果
print(new_df)

    Name  Age       City
0   John   25   New York
1   John   25   New York
2  Alice   30      Paris
3  Alice   30      Paris
4    Bob   35     London