Concatenate Two Dataframes Of Different Sizes (pandas)

I have two dataframes with unique ids. They share some columns but not all. I need to create a combined dataframe which will include rows from missing ids from the second dataframe

Solution 1:

In this case using combine_first

df1.set_index('id').combine_first(df2.set_index('id')).reset_index()
Out[766]: 
   id  metric1  metric2
0   a    123.0      1.0
1   b     22.0      2.0
2   c    356.0      3.0
3   d    412.0      4.0
4   f     54.0      5.0
5   g    634.0      6.0
6   h     72.0      7.0
7   j    812.0      8.0
8   k    129.0      9.0
9   l    110.0     10.0
10  m    200.0     11.0
11  q    812.0      NaN
12  w    110.0      NaN
13  z    129.0      NaN

Solution 2:

If you have many df to combine probably you'll find pd.concat quite usefull

pd.concat([df_1, df_2, ..., df_n])