How to merge multiple data frame columns in pandas by using index?

Question

I have six pandas data frames like the following. I want to join them by using the id column, which is the index. In the following, I have provided an example with three data frames.

df1 = 
id              cnt1
A000        10
A001        20
A002        30
A010        10
A050        55
...........................
A317        20

df2 = 
id          cnt2
A000        10
A010        20
...........................
A316        20

df3 = 
id          cnt3
A010        20
................................
A318        20

After joining, I need one data frame like the following.

all_df =
id              cnt1    cnt2    cnt3
A000            10      10      0   
A001            20      0       0
A002            30      0       0
A010            10      20      20
A050            55      0       0
............................................................................
A316            0       20      0
A317            20      0       0
A318            0       0       20

Please let me know how to do it. Thanks in advance.

Answer 1

IIUC, you want pd.concat on columns

all_df = pd.concat([df1, df2], axis=1).fillna(0)

print(all_df)

      cnt1  cnt2
id
A000  10.0  10.0
A001  20.0   0.0
A002  30.0   0.0
A010  10.0  20.0
A050  55.0   0.0
A317  20.0   0.0
A316   0.0  20.0