I am using Pandas 1.51 and I’m trying to get the rank of each row in a dataframe in a rolling window that looks ahead by employing FixedForwardWindowIndexer. But I can’t make sense of the results. My code: results: By my reckoning, it should look like: I am basing this on a backward-looking window, which works fine: Any assistance is

# Tag: rolling-computation

## Pandas lagged rolling average on aggregate data with multiple groups and missing dates

I’d like to calculate a lagged rolling average on a complicated time-series dataset. Consider the toy example as follows: This results in the following DataFrame: Now I’d like to add a column representing the average weight per fruit for the previous 7 days: wgt_per_frt_prev_7d. It should be defined as the sum of all the fruit weights divided by the sum

## Why does pandas rolling apply throw ValueError when used on axis=1?

Overview I am getting a ValueError when trying to apply a simple function over a dataframe with axis=1 (details below). It looks like it is trying to unpack the output into the columns of the dataframe instead of rows. The problem seems to be related to the apply() specifically, and only occurs when axis=1 is used. Why is this error

## Apply function to each unique value of column seperately

I have a dataframe with more than 500 cities which look like this city value datetime london 23 2022-03-25 17:59:18 dubai 12 2022-03-25 17:59:36 berlin 5 2022-03-25 17:59:42 london 25 2022-03-25 18:01:18 dubai 12 2022-03-25 18:02:18 berlin 5 2022-03-25 18:03:18 I have a function called rolling_mean which creates a new column ‘rolling_mean’ which calculates the last hour rolling average. However

## Getting Rolling Sum per Group

I have a dataframe like this: I would like to get the Sum of the last three months (excluding the current month), per Product_ID. Therefore I tried this: My code is failing, because it does not only calculate it per product, but it will give me also numbers for other products (let’s say Product 2, quarter 1: gives me the

## Pandas: Rolling window to count the frequency – Fastest approach

I would like to count the frequency of a value for the past x days. In the example below, I would like to count the frequency of value in the Name column for the past 28 days. The data is already sorted by Date I found some solutions on StackOverFlow but all of them are neither correct on the dataset

## Datetime rolling count per category in Pandas

Starting from a DataFrame with a date and user column, I’d like to add a third count_past_5_days column to indicate the rolling count of occurrences of each row’s user during the past 5 days: date user count_past_5_days 2020-01-01 abc 1 2020-01-01 def 1 2020-01-02 abc 2 2020-01-03 abc 3 2020-01-04 abc 4 2020-01-04 def 2 2020-01-04 ghi 1 2020-01-05 abc

## Find the row offset for the maximum value over the next N rows in Pandas?

I have some data in a Pandas DataFrame: and I am trying to get the offset for the maximum of the next N rows. For example, when ****, the output would look like I can get the value of the maximum over the next N rows using: However, is it possible to get the row offset position for the maximum

## How to calculate 12 month rolling sum based on groupby?

I am trying to calculate the 12 month rolling sum for the number of orders and revenue based on a person’s name using Python for the following dataframe: In order to give the following output: The rolling sum should add up all the totals in the past 12 months grouped by the name column. I have tried the following: but

## non fixed rolling window

I am looking to implement a rolling window on a list, but instead of a fixed length of window, I would like to provide a rolling window list: Something like this: and the result would be: 6.67 is calculated as average of 3 elements 10, 2, 8. I implemented a slow solution, and every idea is welcome to make it