Data Science · मराठी आवृत्ती

25.3 cumsum — running totals

By Ravindra Bagale

या course चे सर्व chapters (py + ch)

हे का शिकायचं?

दिवसाने जोडलेली गती दिसते — महिन्याचा midway target.

हे काय आहे?

Sort by date → cumsum on amount. Order चुकीचा तर cumulative चुकीचं.

कसं करायचं?

Step 1. Date ने sort.

Step 2. cumsum.

Step 3. शेवटची value = total.

Step 4. Plot optional.

उदाहरणं: copy करा आणि चालवा

उदाहरण A — Festival week (fictional).

import pandas as pd

week = pd.DataFrame({
    "order_date": pd.to_datetime(
        ["2026-10-20", "2026-10-21", "2026-10-22", "2026-10-23", "2026-10-24"]
    ),
    "gmv": [82000, 91000, 88000, 125000, 140000],
    "city_note": ["Mon", "Tue", "Wed", "Thu Diwali eve", "Fri"],
})
week = week.sort_values("order_date")
week["gmv_running"] = week["gmv"].cumsum()
print(week)

उदाहरण B — Share of running total.

week["pct_of_week_so_far"] = (week["gmv_running"] / week["gmv"].sum() * 100).round(1)
print(week[["order_date", "gmv", "gmv_running", "pct_of_week_so_far"]])

उदाहरण C — Cumcount for order sequence.

orders = pd.DataFrame({
    "order_id": ["BLK-a", "BLK-b", "BLK-c"],
    "city": ["Pune", "Pune", "Pune"],
})
orders["seq"] = range(1, len(orders) + 1)  # simple
# or: orders["seq"] = orders.groupby("city").cumcount() + 1
print(orders)