返回组中值的中值。
Syntax
from pyspark.sql import functions as sf
sf.median(col)
参数
| 参数 | 类型 | Description |
|---|---|---|
col |
pyspark.sql.Column 或列名 |
要计算的目标列。 |
退货
pyspark.sql.Column：组中值的中值中值。
例子
from pyspark.sql import functions as sf
df = spark.createDataFrame([
("Java", 2012, 20000), ("dotNET", 2012, 5000),
("Java", 2012, 22000), ("dotNET", 2012, 10000),
("dotNET", 2013, 48000), ("Java", 2013, 30000)],
schema=("course", "year", "earnings"))
df.groupby("course").agg(sf.median("earnings")).show()
+------+----------------+
|course|median(earnings)|
+------+----------------+
| Java| 22000.0|
|dotNET| 10000.0|
+------+----------------+