Data Science Prerequisites - Numpy, Matplotlib, and Pandas in Python - The apply() Function

The video tutorial explains the use of the apply function in Python to perform operations on data frames without using slow for loops. It provides an example of extracting the year from a date column and applying this operation to each row of a data frame. The tutorial also covers how to assign the result to a new column, demonstrating the efficiency and utility of the apply function.

What is the significance of the argument 'axis=1' when using the apply function?

What does the final data frame look like after applying the function to extract the year?