Pivot with aggregation functions in Pandas - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the pivot_table function in pandas do?

It reshapes data by summarizing values using aggregation functions, creating a new table where rows and columns are defined by specified keys.

beginner

Which parameter in pivot_table specifies the column to aggregate?

The values parameter specifies which column's data will be aggregated in the pivot table.

beginner

How do you specify the aggregation function in a pandas pivot table?

Use the aggfunc parameter to set the aggregation function, like sum, mean, or len.

intermediate

What happens if you don't specify an aggregation function in pivot_table?

By default, pivot_table uses the mean function to aggregate values.

intermediate

Can you use multiple aggregation functions in a single pivot table?

Yes, by passing a list of functions to aggfunc, you can apply multiple aggregations like ['sum', 'mean'].

What parameter defines the rows in a pandas pivot table?

A index

B columns

C values

D aggfunc

The index parameter sets the rows in the pivot table.

Which aggregation function is the default in pivot_table?

A mean

B sum

C count

D max

If no aggregation function is specified, mean is used by default.

How do you aggregate data by counting entries in a pivot table?

A aggfunc='sum'

B aggfunc='count'

C aggfunc='mean'

D aggfunc='max'

Use aggfunc='count' to count the number of entries.

Which parameter sets the columns in a pandas pivot table?

A aggfunc

B index

C values

D columns

The columns parameter defines the columns in the pivot table.

Can you apply more than one aggregation function in a pivot table?

A No, only one function is allowed

B No, you must create multiple pivot tables

C Yes, by passing a list to aggfunc

D Yes, but only sum and mean

Passing a list like aggfunc=['sum', 'mean'] applies multiple aggregations.

Explain how to create a pivot table in pandas that sums sales by region and product.

Think about which parts of the data become rows, columns, and what you want to add up.

Describe how you can use multiple aggregation functions in one pivot table and why it might be useful.

Consider why seeing both total and average values together can help understand data better.