import pandas as pd

sales = pd.DataFrame(
    {
        "region": ["East", "East", "East", "West", "West", "West", "North", "North"],
        "quarter": ["Q1", "Q1", "Q2", "Q1", "Q2", "Q2", "Q1", "Q3"],
        "category": [
            "hardware",
            "software",
            "hardware",
            "hardware",
            "hardware",
            "software",
            "software",
            "hardware",
        ],
        "revenue": [1200, 800, 950, 1400, 1100, 650, 500, 700],
    }
)

pivot = pd.pivot_table(
    sales,
    values="revenue",
    index="region",
    columns="quarter",
    aggfunc="sum",
    fill_value=0,
    margins=True,
    margins_name="Total",
)

print(pivot.to_string())
print()
print("West Q2 revenue:", pivot.loc["West", "Q2"])
print("grand total:", pivot.loc["Total", "Total"])

expected = (
    sales.groupby(["region", "quarter"])["revenue"]
    .sum()
    .unstack(fill_value=0)
)

assert pivot.loc["West", "Q2"] == expected.loc["West", "Q2"]
assert pivot.loc["Total", "Total"] == sales["revenue"].sum()

print("verification: pivot totals match grouped source data")