計算每個組數值欄位的總和。
語法
sum(*cols)
參數
| 參數 | 類型 | 說明 |
|---|---|---|
cols |
str | 數據行名稱。 非數字欄位則被忽略。 |
退貨
DataFrame
Examples
df = spark.createDataFrame([
(2, "Alice", 80), (3, "Alice", 100),
(5, "Bob", 120), (10, "Bob", 140)], ["age", "name", "height"])
# Group-by name, and calculate the sum of the age in each group.
df.groupBy("name").sum("age").sort("name").show()
# +-----+--------+
# | name|sum(age)|
# +-----+--------+
# |Alice| 5|
# | Bob| 15|
# +-----+--------+
# Calculate the sum of the age and height in all data.
df.groupBy().sum("age", "height").show()
# +--------+-----------+
# |sum(age)|sum(height)|
# +--------+-----------+
# | 20| 440|
# +--------+-----------+