GroupBy Basics

GroupBy is a powerful feature that lets you split data into groups, apply functions, and combine results.

Basic GroupBy

Group by a column and aggregate:

Multiple Aggregations

Apply different functions:

GroupBy Multiple Columns

Group by more than one column:

Aggregating Multiple Columns

Apply aggregation to several columns:

Iterating Over Groups

Access each group separately:

Getting a Specific Group

Access a single group:

Exercise: Average by Group

Exercise: Count by Group

Key Points

• groupby() splits data into groups
• Apply aggregations like mean(), sum(), count()
• agg() applies multiple functions
• Group by multiple columns with a list
• Iterate with for name, group in grouped
• .get_group() retrieves a specific group