Databricks Data Engineer Associate Question 157
Select 2You are working with a timestamp column named event_time in a Delta table. You need to extract the day of the week and the year from this column. Which of the following functions can you use in PySpark to retrieve this information?
- A
date_format(col('event_time'), 'EEEE') to extract the day of the week and year(col('event_time')) to extract the year
- B
dayofweek(col('event_time')) to extract the day of the week and year(col('event_time')) to extract the year
- C
date_part('dayofweek', col('event_time')) to extract the day of the week and date_part('year', col('event_time')) to extract the year
- D
date_format(col('event_time'), 'yyyy') to extract the year and day(col('event_time')) to extract the day of the week
Show answer and explanation
Correct answers: A, B
Explanation
To extract calendar data such as the day of the week and the year from a timestamp in PySpark, you can use date_format with appropriate patterns (e.g., 'EEEE' for the day name) or dedicated functions like dayofweek and year. Both options (1 and 2) are valid methods for achieving this task in PySpark. Options 3 and 4 are incorrect due to the use of invalid functions or misinterpretation of function behavior.
- A. Correct.
This is correct.
date_formatwith the 'EEEE' pattern extracts the full name of the day of the week (e.g., 'Monday'), andyearextracts the year from a timestamp column. - B. Correct.
This is correct.
dayofweekextracts the day of the week as a numeric value (1-7, starting with Sunday), andyearextracts the year from a timestamp column. - C. Incorrect.
This is incorrect.
date_partis not a function available in PySpark for extracting parts of a timestamp. It is commonly used in other SQL-based systems, but not in PySpark. - D. Incorrect.
This is incorrect. While
date_formatwith the 'yyyy' pattern correctly extracts the year, thedayfunction does not extract the day of the week; rather, it extracts the day of the month.