1. concat竖着拼接(默认的竖着,axis=0)
话不多说,直接看例子:
import pandas as pd
df1=pd.DataFrame([10,12,13])
df2=pd.DataFrame([22,33,44,55])
df3=pd.DataFrame([90,94])
df1
df2
df3
res= pd.concat([df1,df2,df3])
res
|
0 |
0 |
10 |
1 |
12 |
2 |
13 |
0 |
22 |
1 |
33 |
2 |
44 |
3 |
55 |
0 |
90 |
1 |
94 |
如果要生成新索引,忽略原来索引怎么办?
默认有个参数ignore_index= False,将其值改为True:
res2= pd.concat([df1,df2,df3], ignore_index=True)
res2
|
0 |
0 |
10 |
1 |
12 |
2 |
13 |
3 |
22 |
4 |
33 |
5 |
44 |
6 |
55 |
7 |
90 |
8 |
94 |
2. concat横着拼接
用参数axis= 1,看例子:
res_heng= pd.concat([df1,df2,df3], axis=1)
res_heng
|
0 |
0 |
0 |
0 |
10.0 |
22 |
90.0 |
1 |
12.0 |
33 |
94.0 |
2 |
13.0 |
44 |
NaN |
3 |
NaN |
55 |
NaN |