pd.Grouper is a utility in pandas used with .groupby() to flexibly group data by a specific column, often useful for time-based grouping, multi-index grouping, or applying custom frequency aggregation.
See:
Why Use pd.Grouper?
- Allows more readable and declarative code when working with time-indexed data.
- Supports multi-index groupings without restructuring your data.
- Enables resampling-like grouping without setting the index.
Syntax
pd.Grouper(key=None, level=None, freq=None, axis=0, sort=False)Parameters
key: The column name to group by.level: For MultiIndex, the level to group by.freq: Used to group time-series data (e.g.,'D'for daily,'M'for monthly).axis: Default is 0 (rows).sort: Whether to sort the result.