python - 将 pandas 数据框与对象合并

Question

我正在尝试在键“id”上合并 3 个 pandas 数据帧，但不知何故无法得到正确的结果。

最后，我想要一个包含 2 行的数据框，一个具有 id 'abc' 和对象 (something, 1), (something1,1) 和一个 id 'def' 与 object2 (something,1) 和对象 (something, 1）。有没有办法用熊猫来实现这一点？

import pandas as pd
df1 = pd.DataFrame([[]])
df1['id'] ='abc'
df1['object'] = -1
df1['object'] = df1['object'].astype('object')
df1.at[0,'object'] = ('something', 1)
df1['object3'] = -1
df1['object3'] = df1['object3'].astype('object')
df1.at[0,'object3'] = ('something1', 1)

df2 = pd.DataFrame([[]])
df2['id'] ='def'
df2['object2'] = -1
df2['object2'] = df2['object2'].astype('object')
df2.at[0,'object2'] = ('something2', 1)


df3 = pd.DataFrame([[]])
df3['id'] ='def'
df3['object3'] = -1
df3['object3'] = df3['object3'].astype('object')
df3.at[0,'object3'] = ('something3', 1)

编辑：

抱歉，我最初的问题并不清楚：我希望数据框最终看起来像以下内容：

| id  | object          | object2          | object3          |
|-----|-----------------|------------------|------------------|
| abc | ('something',1) | None             | ('something1',1) |
| def | None            | ('something2',1) | ('something3',1) |

标签： pythonpandasdataframe

Answer 1

concat和groupby

用于first解决潜在的非唯一性。这是相当稳健的。

pd.concat([df1, df2, df3]).groupby('id', as_index=False).first()

    id          object          object3          object2
0  abc  (something, 1)  (something1, 1)              NaN
1  def             NaN  (something3, 1)  (something2, 1)