为什么 pandas explode 方法在我的数据框中不起作用？

Question

这是我的代码：

df = pd.read_csv('my_path\zzounds.csv')
df.head() 

      variation_type       main_image
  ['yellow', 'orange']   ['https://c1.zzounds.com/media/productmedia/fit,600by600/quality,85/GIGBAR_MOVE_ON_TRIPOD_812129-0eddea01276623f9a03cbfdd86eb3bd1.jpg', 'https://c1.zzounds.com/media/productmedia/fit,600by600/quality,85/GIGBAR_MOVE_ON_TRIPOD_812129-0eddea01276623f9a03cbfdd86eb3bd1.jpg']

我试过这个代码

df.explode(['variation_type','main_image'])

但它返回的是原始数据帧。

Answer 1

我相信这是因为 python 很难以这种方式分解多个列。

您可以使用此代码获得我相信您期待的结果

data = {
    ' variation_type' : [['yellow', 'orange']],
    'main_image' : [['https://c1.zzounds.com/media/productmedia/fit,600by600/quality,85/GIGBAR_MOVE_ON_TRIPOD_812129-0eddea01276623f9a03cbfdd86eb3bd1.jpg', 'https://c1.zzounds.com/media/productmedia/fit,600by600/quality,85/GIGBAR_MOVE_ON_TRIPOD_812129-0eddea01276623f9a03cbfdd86eb3bd1.jpg']]
}
df = pd.DataFrame(data)
df.apply(pd.Series.explode)

***注意：这仅在所有“列表”字段长度相同时才有效

Answer 2

由于是从csv文件读取，需要先转换字符串列表

df[['variation_type','main_image']] = df[['variation_type','main_image']].applymap(lambda x: pd.eval(x, local_dict={'nan': np.nan}))
# or
df[['variation_type','main_image']] = df[['variation_type','main_image']].applymap(lambda x: eval(x, {'nan': np.nan}))

df = df.explode(['variation_type','main_image'])

Answer 3

为了缩小问题范围，请注意您问题中显示的数据框确实适用于 explode()。如果您的值是看起来像列表的字符串，那么按照@Ynjxsjmh 的建议，可能需要先将它们转换为列表值。

示例测试代码：

import pandas as pd
df = pd.DataFrame({
'variation_type':[['yellow', 'orange']],
'main_image':[['https://c1.zzounds.com/media/productmedia/fit,600by600/quality,85/GIGBAR_MOVE_ON_TRIPOD_812129-0eddea01276623f9a03cbfdd86eb3bd1.jpg', 'https://c1.zzounds.com/media/productmedia/fit,600by600/quality,85/GIGBAR_MOVE_ON_TRIPOD_812129-0eddea01276623f9a03cbfdd86eb3bd1.jpg']]})
print(df.to_string())

df = df.explode(['variation_type','main_image'])
print(df.to_string())

输入：

     variation_type                                                                                                                                                                                                                                                                  main_image
0  [yellow, orange]  [https://c1.zzounds.com/media/productmedia/fit,600by600/quality,85/GIGBAR_MOVE_ON_TRIPOD_812129-0eddea01276623f9a03cbfdd86eb3bd1.jpg, https://c1.zzounds.com/media/productmedia/fit,600by600/quality,85/GIGBAR_MOVE_ON_TRIPOD_812129-0eddea01276623f9a03cbfdd86eb3bd1.jpg]

输出：

  variation_type                                                                                                                           main_image
0         yellow  https://c1.zzounds.com/media/productmedia/fit,600by600/quality,85/GIGBAR_MOVE_ON_TRIPOD_812129-0eddea01276623f9a03cbfdd86eb3bd1.jpg
0         orange  https://c1.zzounds.com/media/productmedia/fit,600by600/quality,85/GIGBAR_MOVE_ON_TRIPOD_812129-0eddea01276623f9a03cbfdd86eb3bd1.jpg

为什么 pandas explode 方法在我的数据框中不起作用？

why pandas explode method not working in my dataframe?

python

python-3.x

pandas