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pythonpandasgroup-byaggregate-functions

Exclude groups containing just one row instance

I have a pandas table like below with groupby applied to get Groups 0, 1 and 2 as follows:

Group 0 Group 1 Group 2 Count
A X1 577.5000 6
894.8700 2
X2 2697.3100 48
2697.3100 1
B3 2697.3100 30
B RO2 92.46 3
C C12 34.2700 9
39.2700 3
D X55 4.1251 9

How do I filter out rows having just one group variation i.e. Below is how the final DF should look like:

Group 0 Group 1 Group 2 Count
A X1 577.5000 6
894.8700 2
X2 2697.3100 48
2697.3100 1
B3 2697.3100 30
C C12 34.2700 9
39.2700 3
Solution

  • You can keep groups where at least one value from Group 0 is duplicated:

    out = df.loc[df.index.get_level_values('Group 0').duplicated(keep=False)]
print(out)

# Output
                         Count
Group 0 Group 1 Group 2       
A       X1      577.50       6
                894.87       2
        X2      2697.31     48
                2697.31      1
        B3      2697.31     30
C       C12     34.27        9
                39.27        3