The code block shown below contains an error. The code block is intended to return a new DataFrame from DataFrame storesDF where column storeId is of the type string. Identify the error. Code block…

Question

Options

• ACalls to withColumn() cannot create a new column of the same name on which it is operating.
• BDataFrame columns cannot be converted to a new type inside of a call to withColumn().
• CThe call to StringType should not be followed by parentheses.
• DThe column name storeId inside the col() operation should not be quoted.
• EThe cast() operation is a method in the Column class rather than a standalone function.

• A
  3% (1)
• B
  3% (1)
• C
  89% (32)
• D
  6% (2)

Explanation

The code uses cast() as if it were a standalone function - cast(col('storeId'), StringType()) - but cast() is actually a method on the Column class, not a standalone function imported from pyspark.sql.functions. Additionally, StringType used as a type specifier in a cast context should not require instantiation with parentheses. The correct syntax is: storesDF.withColumn('storeId', col('storeId').cast(StringType)) or using the string alias col('storeId').cast('string'). Answer C identifies that StringType should not be followed by parentheses in this context.

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