为什么熊猫爆炸方法不工作在我的数据框架?

Question

下面是我的代码:

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'])

但是它返回的是原始数据帧

Answer 1

由于您是从csv文件中读取的，因此您需要首先转换字符串列表

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 2

我相信这是因为python很难以这种方式爆炸多个列。

你可以使用这段代码来获得我相信你期望的结果

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:只有当所有的"list"字段长度相同

Answer 3

为了缩小问题范围，请注意，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，可能需要首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