Exam Certified Associate Developer for Apache Spark topic 1 question 27 discussion

this is completely wrong explanation. Both D and E has replacement expression, the only difference is how they call the replaced column. Both D and E are correct, but D works for Pyspark 2.0. D and E both work Pyspark 3.0+. Period!

I think what you really mean, "there is no replacement string expression", is for option A. The only difference between A and E, is about the claim of replacement string expression

Almost right but it's not about "String object" but "String value". So the correct answer is indeed the answer E ;)

The correct code block that returns a new DataFrame with column storeDescription where the pattern "Description: " has been removed from the beginning of column storeDescription in DataFrame storesDF is: A. storesDF.withColumn("storeDescription", regexp_replace(col("storeDescription"), "^Description: ")) This code uses the regexp_replace function to replace the pattern "^Description: " (which matches the string "Description: " at the beginning of the string) with an empty string in the column storeDescription. The resulting DataFrame will have the modified storeDescription column. Option B has a syntax error because the regexp_replace function should be called on the column using the dot notation instead of passing it as the second argument. Option C uses the regexp_extract function, which extracts a substring matching a regular expression pattern. It doesn't remove the pattern from the string. Option D has a syntax error because the column name is not wrapped in the col function. Option E is the same as option A, except that it uses the col function unnecessarily.

You got the wrong question :°

Option A is incorrect because the regexp_replace function requires two arguments: the column to be transformed and the regular expression pattern to be replaced. In the given code block, only the regular expression pattern is provided, but not the column to be transformed. The correct syntax to use regexp_replace on a DataFrame column is regexp_replace(col(column_name), pattern, replacement), where col(column_name) specifies the DataFrame column to be transformed, pattern specifies the regular expression pattern to be replaced, and replacement specifies the new string to replace the matched pattern. Therefore, the correct code block to remove the pattern "Description: " from the beginning of the storeDescription column in DataFrame storesDF is: storesDF.withColumn("storeDescription", regexp_replace(col("storeDescription"), "^Description: ", ""))