A. Подкрутка

import os
import pandas as pd
import kagglehub


path = kagglehub.dataset_download("ersany/online-retail-dataset")
df = pd.read_excel(os.path.join(path, "Online Retail.xlsx"))


def change_price(group):
    first_letter = group.name #A, B, C...

    if first_letter == 'A':
        max_price = group['UnitPrice'].max()
        group['UnitPrice'] = max_price
    elif first_letter == 'B':
        min_price = group['UnitPrice'].min()
        group['UnitPrice'] = group['UnitPrice'] - (min_price / 2)
    else:
        group['UnitPrice'] = group['UnitPrice'] * 1.1

    return group


def task1(df):
    df = df.groupby(df['Country'].str[0], group_keys=False).apply(change_price)

    return df

df = task1(df)