Pivot and Join

Selecting rows based on a condition

Pivot

Read Inferential Thinking

Read Ch 8.3, which describes grouping by multiple columns and a cross-tabulation concept called pivoting.

Before continuing, make sure that:

  • You can compare and contrast how group and pivot aggregate data.
  • You understand the optional arguments to the pivot method: values and collect.

Join

Read Inferential Thinking

Read Ch 8.4, which joins tables together.

Before continuing, make sure that:

  • You understand how joining one table on another augments the information in a table.

  • You can identify the appropriate shared column on which to join two tables.

  • You can compare and contrast the use cases for the different function signatures of the join Table method:

    • tblA.join(colA, tblB)
    • tblA.join(colA, tblB, colB)