DATABRICKS-CERTIFIED-ASSOCIATE-DEVELOPER-FOR-APACHE-SPARK · Question #111
Which of the following code blocks returns a 15 percent sample of rows from DataFrame storesDF without replacement?
The correct answer is B. storesDF.sample(fraction = 0.15). The PySpark DataFrame sample() method signature is sample(withReplacement=False, fraction=None, seed=None). The default for withReplacement is False, so calling storesDF.sample(fraction=0.15) returns a 15% sample WITHOUT replacement - exactly what the question asks for. Choice…
Question
Which of the following code blocks returns a 15 percent sample of rows from DataFrame storesDF without replacement?
Options
- AstoresDF.sample(True, fraction = 0.15)
- BstoresDF.sample(fraction = 0.15)
- CstoresDF.sampleBy(fraction = 0.15)
- DstoresDF.sample(fraction = 0.10)
- EstoresDF.sample()
How the community answered
(35 responses)- A3% (1)
- B89% (31)
- C6% (2)
- E3% (1)
Explanation
The PySpark DataFrame sample() method signature is sample(withReplacement=False, fraction=None, seed=None). The default for withReplacement is False, so calling storesDF.sample(fraction=0.15) returns a 15% sample WITHOUT replacement - exactly what the question asks for. Choice A passes True as the first positional argument, enabling sampling WITH replacement, which is wrong. Choice C uses sampleBy(), which is for stratified sampling and requires a column and fractions dictionary. Choice D uses fraction=0.10, which gives a 10% sample, not 15%. Choice E omits the required fraction argument entirely.
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