How to do extract output from different data frames

Question

two column of 1 data frame and other two column of 2nd data frame now extract the value use by these two data frame

df1[["source", "Tar"]       df2["id", "me"]

source    Tar                  id        me
cd1        ef2                 60_2       ac4
cd1       hi1                 50_6        xg3
zx2        an2
cd1      60_2
zx2      50_6

Output should be

df1["source" , "Tar"]

source    Tar                  
cd1       ef2                 
cd1       hi1                 
zx2       an2
cd1       ac4
zx2       xg3

score 0 · Accepted Answer · answered Mar 31 '22 at 09:14

0

You can perform a left merge and combine_first:

df1['Tar'] = (df1
              .merge(df2, left_on='Tar', right_on='id', how='left')
              ['me'].combine_first(df1['Tar'])
             )

Or map the values using a Series crafted from df2:

df1['Tar'] = df1['Tar'].map(df2.set_index('id')['me']).fillna(df1['Tar'])

output:

  source  Tar
0     cd  ef2
1     ab  hi1
2     zx  an2
3     yz  ac4
4     xy  xg3

answered Mar 31 '22 at 09:14

mozway

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Reindexing only valid with uniquely valued Index objects......error throw – Rati Goyal Mar 31 '22 at 10:02
@RatiGoyal can you edit your question to add a [reproducible pandas example](https://stackoverflow.com/questions/20109391/how-to-make-good-reproducible-pandas-examples) of the input dataframes? It looks like you have duplicates, please include this in the example, how should this case be handled? – mozway Mar 31 '22 at 10:03
now edited, plz check – Rati Goyal Mar 31 '22 at 10:23
please solve as soon as possible – Rati Goyal Mar 31 '22 at 10:40
@RatiGoyal my code produces the expected output, can you provide your real dataset? – mozway Mar 31 '22 at 11:25
i hv editted the question, plz do according to question. – Rati Goyal Mar 31 '22 at 11:32
real data set is too big not possible to share – Rati Goyal Mar 31 '22 at 11:33
You can provide a chosen sample that reproduces the issue. – mozway Mar 31 '22 at 11:34
Has it solved your problem? – mozway Apr 02 '22 at 06:48

How to do extract output from different data frames

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