pyspark.RDD.top¶
-
RDD.top(num: int, key: Optional[Callable[[T], S]] = None) → List[T][source]¶ Get the top N elements from an RDD.
New in version 1.0.0.
- Parameters
- numint
top N
- keyfunction, optional
a function used to generate key for comparing
- Returns
- list
the top N elements
See also
Notes
This method should only be used if the resulting array is expected to be small, as all the data is loaded into the driver’s memory.
It returns the list sorted in descending order.
Examples
>>> sc.parallelize([10, 4, 2, 12, 3]).top(1) [12] >>> sc.parallelize([2, 3, 4, 5, 6], 2).top(2) [6, 5] >>> sc.parallelize([10, 4, 2, 12, 3]).top(3, key=str) [4, 3, 2]