pandas pivot table rename columns

Question

How to rename columns with multiple levels after pandas pivot operation?

Here\'s some code to generate test data:

import pandas as pd
df = pd.DataFrame({         


        

Answer 1

If you want to coalesce the multi-index into a single string index without caring about the index level order, you can simply map a join function over the columns, and assign the result list back:

df2.columns = list(map("_".join, df2.columns))

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And for your question, you can loop through the columns where each element is a tuple, unpack the tuple and join them back in the order you want:

df2 = pd.pivot_table(df, index=["c0"], columns=["c01","c02"], values=["v1","v2"])

# Use the list comprehension to make a list of new column names and assign it back
# to the DataFrame columns attribute.
df2.columns = ["_".join((j,k,i)) for i,j,k in df2.columns]
df2.reset_index()