在数据集中查找结构字段的数据类型

Question

I have a dataset, which has the following schema:

ds.schema()
    0 = {StructField@21690} "StructField(col_name_1,NullType,true)"
    1 = {StructField@21691} "StructField(col_name_2,StringType,true)"
    2 = {StructField@21692} "StructField(col_name_3,ArrayType(StructType(StructField(person_name,StringType,true), StructField(person_surname,StringType,true)),true),true)"

I want to access the datatype of each StructField. Eg if the data type of col_name_1 is NullType print null.

How can I build this if loop?

Answer 1

You can pull this out of the schema:

 for field in df.schema.fields: print(field.name +" , "+str(field.dataType))

Answer 2

这对我来说很好：

ds.schema().apply(ColName).dataType().toString().equals("NullType")