Multiple Aggregations

The agg() function provides powerful ways to apply multiple aggregations to grouped data.

Named Aggregations

Use named tuples for clear output:

Different Aggregations per Column

Apply different functions to different columns:

Custom Aggregation Functions

Use your own functions:

Aggregation with Lambda

Use lambda for inline functions:

Resetting Index After Aggregation

Convert multi-index to regular columns:

Transform vs Aggregate

Transform returns same-size output:

Exercise: Multiple Stats

Exercise: Add Group Mean

Key Points

• agg() for multiple aggregations
• Named aggregations: name=('column', 'function')
• Dict syntax for different functions per column
• Custom functions work with agg()
• transform() returns same-length output
• reset_index() flattens grouped results