将熊猫数据框与对象合并

时间:2020-04-30 16:48:22

标签: python pandas dataframe

我试图在键“ id”上合并3个pandas数据帧,但是以某种方式无法获得正确的结果。

最后,我想要一个具有2行的数据框,其中一个ID为'abc'和对象(something1,1),(something1,1),而ID为'def'的行具有object2(something,1)和对象(某物,1)。 有没有办法用熊猫来做到这一点?

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:

对不起,我最初的问题还不清楚:我希望数据框最后看起来像这样:

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

1 个答案:

答案 0 :(得分:1)

concatgroupby

使用first解决潜在的非唯一性。这相当健壮。

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)