Maybe you can use keys
argument of concat
:
import numpy as np
import pandas as pd
df1 = pd.DataFrame(np.random.rand(3, 2))
df2 = pd.DataFrame(np.random.rand(4, 2))
df3 = pd.DataFrame(np.random.rand(5, 2))
print pd.concat([df1, df2, df3], keys=["A", "B", "C"])
output:
0 1
A 0 0.863774 0.794880
1 0.578503 0.418619
2 0.215317 0.146167
B 0 0.655829 0.116917
1 0.862316 0.812847
2 0.500126 0.689218
3 0.653439 0.270427
C 0 0.825213 0.882963
1 0.579436 0.332047
2 0.456948 0.718893
3 0.795074 0.826773
4 0.049676 0.697471
If you want to append other dataframes later:
df4 = pd.DataFrame(np.random.rand(6, 2))
pd.concat([df, pd.concat([df4], keys=["D"])])