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DATABRICKS-CERTIFIED-ASSOCIATE-DEVELOPER-FOR-APACHE-SPARK · Question #18

Which of the following code blocks returns a 15 percent sample of rows from DataFrame storesDF without replacement?

The correct answer is E. storesDF.sample(fraction = 0.15). storesDF.sample(fraction=0.15) is correct: the fraction parameter specifies the proportion of rows to sample (0.15 = 15%), and the withReplacement parameter defaults to False, meaning sampling is done without replacement. Option A uses fraction=0.10 (10%, not 15%). Option B…

Performing DataFrame Transformations

Question

Which of the following code blocks returns a 15 percent sample of rows from DataFrame storesDF without replacement?

Options

  • AstoresDF.sample(fraction = 0.10)
  • BstoresDF.sampleBy(fraction = 0.15)
  • CstoresDF.sample(True, fraction = 0.10)
  • DstoresDF.sample()
  • EstoresDF.sample(fraction = 0.15)

How the community answered

(23 responses)
  • A
    4% (1)
  • D
    4% (1)
  • E
    91% (21)

Explanation

storesDF.sample(fraction=0.15) is correct: the fraction parameter specifies the proportion of rows to sample (0.15 = 15%), and the withReplacement parameter defaults to False, meaning sampling is done without replacement. Option A uses fraction=0.10 (10%, not 15%). Option B uses sampleBy(), which is a stratified sampling method with a different parameter structure. Option C uses True for withReplacement (i.e., with replacement) and the wrong fraction. Option D passes no arguments, which is invalid. Only E correctly specifies 15% without replacement.

Topics

#DataFrame sampling#Spark DataFrame API#Data transformations

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