Union in more than 2 pandas dataframe

Question

I am trying to convert a sql query to python. The sql statement is as follows:

select * from table 1 
union
select * from table 2
union 
select * from table 3
un         


        

Answer 1

This should be a comment on Jezrael's answer (+1'd for merge over concat) but I haven't sufficient reputation.

The OP asked how to union the dfs, but merge returns intersection by default: http://pandas.pydata.org/pandas-docs/stable/generated/pandas.merge.html#pandas.merge

To get unions, add how='outer' to the merge calls.