Concatenate distinct columns in two dataframes using pandas (and append similar columns)

Question

My question is closely related to Pandas Merge - How to avoid duplicating columns but not identical.

I want to concatenate the columns that are diff

Answer 1

You can extract only those columns from df2 (and df3 similarly) which are not already present in df1. Then just use pd.concat to concatenate the data frames:

cols = [c for c in df2.columns if c not in df1.columns]
df = pd.concat([df1, df2[cols]], axis=1)