python - StructType 不能接受 pyspark 中的对象 float

Question

为什么它工作得很好

from pyspark.sql.types import *
l=[("foo",83.33)]
schema = StructType([
   StructField("type", StringType(), True),
   StructField("value", DoubleType(), True)])
df= spark.createDataFrame(l,schema)

还有这个

 l=[(83.33)]
    schema = StructType([
    StructField("value", DoubleType(), True)])
    df= spark.createDataFrame(l,schema)

给我一​​个错误

StructType can not accept object 83.33 in type <class 'float'>

Answer 1

当使用单元素元组时，尾随逗号是必需的。检查这个TupleSyntax

>>> l=[(83.33,)]           //note the comma (,)
>>> schema = StructType([
...     StructField("value", DoubleType(), True)])
>>> df= spark.createDataFrame(l,schema)
>>> df.show()
+-----+
|value|
+-----+
|83.33|
+-----+