Human: Compare Python Pandas DataFrames for matching rows Assistant: 
Here is some code to find all the rows in Dataframe 'df2' that are also present in Dataframe 'df1', for the columns 'A', 'B', 'C' and 'D'.

pd.merge(df1, df2, on=['A', 'B', 'C', 'D'], how='inner')

#Warning: this code generation is experimental. Please inspect the code for any bugs before executing.