Pretty new to Python, but as an SEO I'm looking at the benefits of using notebooks in my workflow.

I've got two excel files which I've cleaned and imported into a new notebook using pandas.

I'm trying to compare position changes and create a new dataframe with new columns to show previous, new, and changes in positions.

Have a look at the screengrabs[! of the data below. Thanks in advance.

Dataframe1 Dataframe2

  • $\begingroup$ Could you briefly say what you want to do? like say you have dataframe 1 having columns {x, y, ...} and dataframe 2 with columns {z, m, n,...}. Now what are you planning to do with them? What would be the final dataframe? $\endgroup$ Jan 20, 2020 at 1:09

1 Answer 1


You can do a pandas.DataFrame.join if you know how this works.

-- Edit: merge is apparently a better choice: See the example at the end.

I think you need an outer join on Keyword.

This should give a new DataFrame, that contains unique rows for the Keyword in both tables. Some entries may be NULL/None. This indicates that in the old or new table, the keyword was not present and you should treat is as a new keyword, or a keyword that has dropped from the list.

Rename the columns in the new table appropriately, and then apply a smart value between columns, taking into account that some values are NULL.

You can do a similar thing in Excel: https://superuser.com/questions/1023123/how-to-simulate-a-full-outer-join-in-excel


Minimalistic example:

import pandas as pd

old = pd.DataFrame({'keyword': ['football', 'soccer', 'rugby'], 'position': [2, 1, 3]})
new = pd.DataFrame({'keyword': ['hockey', 'rugby', 'soccer'], 'position': [3, 2, 1]})

old.keyword = old.keyword.astype(str)
new.keyword = new.keyword.astype(str)


old = old.rename(columns={"position": "position_old"})
new = new.rename(columns={"position": "position_new"})


merged = pd.merge(old, new, how='outer', on='keyword')


    keyword  position_old
0  football             2
1    soccer             1
2     rugby             3
  keyword  position_new
0  hockey             3
1   rugby             2
2  soccer             1
    keyword  position_old  position_new
0  football           2.0           NaN
1    soccer           1.0           1.0
2     rugby           3.0           2.0
3    hockey           NaN           3.0
  • $\begingroup$ Thanks for your help, will give it try. $\endgroup$ Jan 19, 2020 at 16:35
  • $\begingroup$ Regrettably still can't get it to work, but thanks for your input. $\endgroup$ Jan 19, 2020 at 18:34
  • $\begingroup$ Thanks so much for the input, that makes sense, thanks for your help. $\endgroup$ Jan 20, 2020 at 7:41

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