Pandas groupby take counts greater than 1

Question

This must be a simple question, but, however, it is bugging my head for a while.

For a dataframe below:

df = pd.DataFrame({\'c0\': [\'a\',\'b\',\'a\'         


        

Answer 1

Use GroupBy.transform for Series with same size like original DataFrame:

df1 = df[df.groupby(['c0','c1'])['c2'].transform('count') > 1]

Or use DataFrame.duplicated for filtered all dupe rows by specified columns in list:

df1 = df[df.duplicated(['c0','c1'], keep=False)]

If performance is in not important or small DataFrame use DataFrameGroupBy.filter:

df1 = df.groupby(['c0','c1']).filter(lambda x: len(x) > 1)