Appending columns from different DataFrames

All DataFrames can add new columns to themselves. However, as usual, whenever a DataFrame is adding a new column from another DataFrame or Series, the indexes align first before the new column is created.

Getting ready

This recipe uses the employee dataset to append a new column containing the maximum salary of that employee's department.

How to do it...

1. Import the employee data and select the DEPARTMENT and BASE_SALARY columns in a new DataFrame:

>>> employee = pd.read_csv('data/employee.csv')
>&gt...