How can I merge back the datarame into one in python

Question

In Python : I have two data frame with different index and I want to merge them in such a way that merged data frame will have same index.

For example:

df1 = index  Values1
      0        a
      1        b
      2        c
      3        d
      9        i
      10       j

 df2 = index  Values1
       4        f
       5        g
       6        h
       7        n
       8        m

Result that I want is:

df3 = index Values1
      0        a      
      1        b      
      2        c      
      3        d       
      4        f
      5        g
      6        h
      7        n
      8        m
      9        i
      10       j

I thank you for your time and help.