Python combine two dataframes

Question

given two data frames:

a=pd.DataFrame({'col1':[1],'col2':[4]},index=[0])
b=pd.DataFrame({'col3':[7],'col4':[8]},index=[1])

how do I get dataframe c:

c=pd.DataFrame({'col1':[1],'col2':[4],'col3':[7],'col4':[8]},index=[1])

vijaykumar · Accepted Answer · 2015-03-17 08:40:05Z

1

Try this .i believe you can use the append

c = a.append(b,True)

answered Mar 17, 2015 at 8:40

vijaykumar

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1 Comment

,thanks. But there's a mismatch of index between a and b. You solution gives a dataframe with two rows. How can I get a one row result?

EdChum · Accepted Answer · 2015-03-17 09:06:41Z

1

Because you have a mismatch on your indices you have to overwrite them:

In [66]:

a.index=b.index
pd.concat([a,b], axis=1)
Out[66]:
   col1  col2  col3  col4
1     1     4     7     8

If you didn't do this then you get an additional row:

In [71]:

pd.concat([a,b], axis=1)
Out[71]:
   col1  col2  col3  col4
0     1     4   NaN   NaN
1   NaN   NaN     7     8

answered Mar 17, 2015 at 9:06

EdChum

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