选择特定列时的 NaN 值

Question

目前正在尝试使用 Pandas 和 Matplotlib 收集一些有关数据科学的知识。

我想做什么
Select 租用私人房间 (AirBnB) 相应价格的社区组

问题
我为一列获得了正确的数据，但对于其余列，我收到了 NaN 值。感谢任何帮助，您可以在下面找到代码片段和输出。

    ap_df = pd.DataFrame()

for neighbourhood_group in df['neighbourhood_group'].unique():
    nbhg_df = df.copy()[df['neighbourhood_group']==neighbourhood_group]
    nbhg_df[f"{neighbourhood_group}_Price"] = nbhg_df['price']
    nbhg_df.set_index("id", inplace=True)
    nbhg_df.sort_index(inplace=True)
    if ap_df.empty:
        ap_df = nbhg_df[[f"{neighbourhood_group}_Price"]]
    else:
        ap_df = ap_df.join(nbhg_df[f"{neighbourhood_group}_Price"])

ap_df

Output I receive after performing the above Code

Answer 1

所以我想我可以帮助您提供另一个更简单且可以满足您需求的示例

import pandas

df = pandas.DataFrame({
    'id': [1, 2, 3],
    'cat': ['cat_1', 'cat_2', 'cat_3'],
    'price': [1, 2, 3]
})

df.set_index(df['id'], drop=True, inplace=True)
new_df = pandas.DataFrame(index=df.index)

for var in df['cat'].unique():
    new_df[f'{var}_price'] = df[df['cat'] == var]['price']


new_df

输出：

    cat_1_price   cat_2_price   cat_3_price
id          
1    1.0             NaN             NaN
2    NaN             2.0             NaN
3    NaN             NaN             3.0

选择特定列时的 NaN 值

NaN Values when selecting specific columns

python

nan

pandas