When grouping by DataFrame the order does matter and may be surprising.

Trying to give an intuitive understanding what's the difference between a biased and unbiased estimators of variance of a sample.

A gotcha when aggregated time series data involving hourly based counts.

(Original notebooks can be found in this gist) Assume you have data set as follows: ID Date Value x x x where each row contains an ID, a date (given as pd.Datetime) and a value. The objective is to count how many rows occur in each day. import pandas …

Benchmarking different ways to process two columns simultaneously.

TL;DR The function pandas.DataFrame.values is not the inverse of pd.DataFrame(np.array). Introduction An important part of reproducible data science work, is the ability to apply the DAG on the very same dataset. Simplest option is to commit the datasets to a VCS like git. This …