stack_according_to_a_reference.py

import pandas as pd

## unstack a timeseries target variable according to a categorical reference column 
def unstack_ts_according_to_reference(df:pd.DataFrame, c_dt:str, c_cat_reference:str, c_target_variable:str)->pd.DataFrame:
    """
    Unstack a timeseries target variable according to a categorical reference column.
    df -- Dataframe to be processed.
    c_dt -- Temporal column.
    c_cat_reference -- Categorical column to be used as reference to stack the target variable.
    c_target_variable -- Num / Cat column to be stacked.
    return -- stacked dataframe(index -- values of c_dt / column names -- values of c_cat_reference)
    """
    # validate arguments
    assert isinstance(df, pd.DataFrame) and len(df)>0
    assert c_dt in df.columns.tolist()
    assert c_cat_reference in df.columns.tolist()
    assert df[c_cat_reference].dtype.kind  is 'O'
    assert c_target_variable in df.columns.tolist()
    # unstack
    temp = df[[c_dt, c_cat_reference, c_target_variable]].set_index([c_dt, c_cat_reference]).unstack()
    # reset column names
    temp.columns = temp.columns.get_level_values(1)
    # return
    return temp