透過在現有陣列中附加一個值來回傳新的陣列欄位。
語法
from pyspark.sql import functions as sf
sf.array_append(col, value)
參數
| 參數 | 類型 | Description |
|---|---|---|
col |
pyspark.sql.Column 或 str |
包含陣列的欄位名稱。 |
value |
任意 | 一個字面值，或是要附加到陣列中的欄位運算式。 |
退貨
pyspark.sql.Column：一個附加 value 於原始陣列的新陣列欄位。
範例
範例 1：將欄位值附加到陣列欄位
from pyspark.sql import Row, functions as sf
df = spark.createDataFrame([Row(c1=["b", "a", "c"], c2="c")])
df.select(sf.array_append(df.c1, df.c2)).show()
+--------------------+
|array_append(c1, c2)|
+--------------------+
| [b, a, c, c]|
+--------------------+
範例 2：在陣列欄位附加數值
from pyspark.sql import functions as sf
df = spark.createDataFrame([([1, 2, 3],)], ['data'])
df.select(sf.array_append(df.data, 4)).show()
+---------------------+
|array_append(data, 4)|
+---------------------+
| [1, 2, 3, 4]|
+---------------------+
範例 3：在陣列欄位附加空值
from pyspark.sql import functions as sf
df = spark.createDataFrame([([1, 2, 3],)], ['data'])
df.select(sf.array_append(df.data, None)).show()
+------------------------+
|array_append(data, NULL)|
+------------------------+
| [1, 2, 3, NULL]|
+------------------------+
範例 4：將值附加到 NULL 陣列欄位
from pyspark.sql import functions as sf
from pyspark.sql.types import ArrayType, IntegerType, StructType, StructField
schema = StructType([
StructField("data", ArrayType(IntegerType()), True)
])
df = spark.createDataFrame([(None,)], schema=schema)
df.select(sf.array_append(df.data, 4)).show()
+---------------------+
|array_append(data, 4)|
+---------------------+
| NULL|
+---------------------+
範例 5：將值附加到空陣列
from pyspark.sql import functions as sf
from pyspark.sql.types import ArrayType, IntegerType, StructType, StructField
schema = StructType([
StructField("data", ArrayType(IntegerType()), True)
])
df = spark.createDataFrame([([],)], schema=schema)
df.select(sf.array_append(df.data, 1)).show()
+---------------------+
|array_append(data, 1)|
+---------------------+
| [1]|
+---------------------+