使用 to_json 此案例的函数。

df=spark.createDataFrame([("beatles",["help","hey juude"]),("romeo",["eres mia"]),("juliet",None)],["name","hit_songs"])

from pyspark.sql.functions import *

df.groupBy(lit(1)).\
agg(collect_list(to_json(struct('name','hit_songs'))).alias("json")).\
drop("1").\
show(10,False)

# +-------------------------------------------------------------------------------------------------------------------+

# |json                                                                                                               |

# +-------------------------------------------------------------------------------------------------------------------+

# |[{"name":"beatles","hit_songs":["help","hey juude"]}, {"name":"romeo","hit_songs":["eres mia"]}, {"name":"juliet"}]|

# +-------------------------------------------------------------------------------------------------------------------+

# using toJSON function.

df.groupBy(lit(1)).\
agg(collect_list(struct('name','hit_songs')).alias("json")).\
drop("1").\
toJSON().\
collect()

# [u'{"json":[{"name":"beatles","hit_songs":["help","hey juude"]},{"name":"romeo","hit_songs":["eres mia"]},{"name":"juliet"}]}']