Append new level to DataFrame column-CodePudding

Given a DataFrame, how can I add a new level to the columns based on an iterable given by the user? In other words, how do I append a new level?

The question How to simply add a column level to a pandas dataframe shows how to add a new level given a single value, so it doesn't cover this case.

Here is the expected behaviour:

>>> df = pd.DataFrame(0, columns=["A", "B"], index=range(2))
>>> df
    A   B
0   0   0
1   0   0
>>> append_level(df, ["C", "D"])
    A   B
    C   D
0   0   0
1   0   0

CodePudding user response：

def append_level(df, new_level):
    new_df = df.copy()
    new_df.columns = pd.MultiIndex.from_tuples(zip(*zip(*df.columns), new_level))
    return new_df

CodePudding user response：

I believe you can just do:

df.columns = pd.MultiIndex.from_arrays([df.columns.tolist(), ['C','D']])