不多说看代码：
import pandas as pd
import numpy as np
df = pd.DataFrame(np.random.randn(5,4))
df1 = pd.DataFrame(np.random.randn(3,4))
df2 = pd.DataFrame(np.random.randn(3,4))
print(df)
print(df.iloc[0:3,:])#切开前三行
print(df1)
print(df2)
print(pd.concat([df1, df2], ignore_index=True))#合并df1+df2
运行结果：
0 1 2 3
0 -0.905734 -1.984248 -0.804332 -0.659593
1 -1.903482 -0.432071 0.149107 -1.125988
2 -1.811088 0.128598 0.958648 -0.059884
3 1.914469 -0.155695 1.475895 0.131296
4 0.990463 1.515627 -0.875387 -1.397807
0 1 2 3
0 -0.905734 -1.984248 -0.804332 -0.659593
1 -1.903482 -0.432071 0.149107 -1.125988
2 -1.811088 0.128598 0.958648 -0.059884
0 1 2 3
0 0.100466 1.506926 1.509604 0.727146
1 -0.954037 0.572776 1.393201 1.406746
2 -0.706245 0.408888 -1.581230 -0.565017
0 1 2 3
0 -0.458960 -0.246514 -0.340165 0.987064
1 0.829132 0.465937 -0.285688 -0.953261
2 -0.562739 -0.630129 0.846015 1.387031
0 1 2 3
0 0.100466 1.506926 1.509604 0.727146
1 -0.954037 0.572776 1.393201 1.406746
2 -0.706245 0.408888 -1.581230 -0.565017
3 -0.458960 -0.246514 -0.340165 0.987064
4 0.829132 0.465937 -0.285688 -0.953261
5 -0.562739 -0.630129 0.846015 1.387031
Process finished with exit code 0
