沧海拾珠

Pandas 连接数据集

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1. 连接两个dataframe数据集

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import numpy as np
import pandas as pd
from pandas import Series, DataFrame
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df_1 = DataFrame(np.arange(16).reshape(4,4))
	0	1	2	3
0	0	1	2	3
1	4	5	6	7
2	8	9	10	11
3	12	13	14	15
df_2 = DataFrame(np.arange(4).reshape(2,2))
	0	1
0	0	1
1	2	3
# 将df_1和df_2连接起来
pd.concat([df_1,df_2],axis = 1) #在列上进行连接。pd.concat([df_1,df_2])表示在行上进行连接
0	1	2	3	0	1
0	0	1	2	3	0.0	1.0
1	4	5	6	7	2.0	3.0
2	8	9	10	11	NaN	NaN
3	12	13	14	15	NaN	NaN    
# 另外一种连接方法
df_1.append(df_2,ignore_index = True)

2.将dataframe 和series连接起来

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series = Series([3,4,5,6])
series.name = 'added_series'
pd.concat([df_1,series],axis = 1)
0	1	2	3	added_series
0	0	1	2	3	3
1	4	5	6	7	4
2	8	9	10	11	5
3	12	13	14	15	6

3.去掉指定行或者列

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df_1.drop([0,1])
0	1	2	3
2	8	9	10	11
3	12	13	14	15
df_1.drop([0,1],axis = 1)
2	3
0	2	3
1	6	7
2	10	11
3	14	15