I have 2 Data Frames, one named USERS and another named EXCLUDE. Both of them have a field named “email”. Basically, I want to remove every row in USERS that has an email contained in EXCLUDE. How can I do it? Answer You can use boolean indexing and condition with isin, inverting boolean Series is…
Tag: merge
pandas – Merging on string columns not working (bug?)
I’m trying to do a simple merge between two dataframes. These come from two different SQL tables, where the joining keys are strings: I try to merge them using this: The result of the inner join is empty, which first prompted me that there might not be any entries in the intersection: But when I try to …
How to merge two dataframe in pandas to replace nan
I want to do this in pandas: I have 2 dataframes, A and B, I want to replace only NaN of A with B values. Answer The official way promoted exactly to do this is A.combine_first(B). Further information are in the official documentation. However, it gets outperformed massively with large databases from A.fillna…
Python Pandas merge only certain columns
Is it possible to only merge some columns? I have a DataFrame df1 with columns x, y, z, and df2 with columns x, a ,b, c, d, e, f, etc. I want to merge the two DataFrames on x, but I only want to merge columns df2.a, df2.b – not the entire DataFrame. The result would be a DataFrame with
How to merge dictionaries of dictionaries?
I need to merge multiple dictionaries, here’s what I have for instance: With A B C and D being leaves of the tree, like {“info1″:”value”, “info2″:”value2”} There is an unknown level(depth) of dictionaries, it could be {2:{“c”:{“z”:{…