python - How to subtract rows of one pandas data frame from another?

Question

The operation that I want to do is similar to merger. For example, with the inner merger we get a data frame that contains rows that are present in the first AND second data frame. With the outer merger we get a data frame that are present EITHER in the first OR in the second data frame.

What I need is a data frame that contains rows that are present in the first data frame AND NOT present in the second one? Is there a fast and elegant way to do it?

Answer 1

Consider Following:

1. df_one is first DataFrame
2. df_two is second DataFrame

Present in First DataFrame and Not in Second DataFrame

Solution: by Index df = df_one[~df_one.index.isin(df_two.index)]

index can be replaced by required column upon which you wish to do exclusion. In above example, I've used index as a reference between both Data Frames

Additionally, you can also use a more complex query using boolean pandas.Series to solve for above.