I wanted to know if there was a way to verify if a value in one df that was being Concatenated with another existed in both dfs or the other df as well prior to stacking them on top of each other??
I had two dfs as
df = pd.concat([df1, df2])
df = df.sort_values(by=['id', 'timestamp']).reset_index(drop=True)
df
id timestamp
0 1 1959-06-01
1 1 2019-01-01
2 1 2019-01-02
3 2 1989-12-01
4 2 2019-01-15
5 3 1999-01-25
6 3 2019-01-17
7 3 2019-02-01
8 3 2019-02-03
Was there a way to to verify that the I.D in df1 existed in df2 before concatenating similar to a merge? I didn't need to merge but instead concatenate the dfs on top of each other.
One df has multiple ids and timestamps and the other had only one ID and I wanted to make sure only IDs that existed in both were in the resulting concatenated df
thanks!
One workaround you can do here is to create a dummy column:
df1["df"] = 1
df2["df"] = 2
df = pd.concat([df1, df2])
That way you can see where each row was derived.