一种使用正则表达式从列表中只拆分第一次出现的方法

An approach using regular expression to split only first occurrence from the list

testdf.withColumn('Food1',f.split('Food',"(?<=^[^,]*)\\,")[0]).\
       withColumn('Food2',f.split('Food',"(?<=^[^,]*)\\,")[1]).show()

+------+---------------+-----+----------+
|Animal|           Food|Food1|     Food2|
+------+---------------+-----+----------+
|   Dog|meat,bread,milk| meat|bread,milk|
|   Cat|     mouse,fish|mouse|      fish|
+------+---------------+-----+----------+