How to store JSON dataframe with comma sepearted

问题

I need to write record of dataframe to a json file. If I write the dataframe into the file it stores like {"a":1} {"b":2}, I want to write the dataframe like this [{"a":1} ,{"b":2}]. Can you please help me. Thanks in advance.

回答1:

Use to_json function to create array of json objects then use .saveAsTextFile to save the json object.

Example:

#sample dataframe
df=spark.createDataFrame([("a",1),("b",2)],["id","name"])

from pyspark.sql.functions import *

df.groupBy(lit("1")).\
agg(collect_list(struct(*[df.columns])).alias("cl")).\
select(to_json("cl").alias("jsn")).\
rdd.\
map(lambda x:x["jsn"]).\
saveAsTextFile("<path>")

cat <path>
#[{"id":"a","name":1},{"id":"b","name":2}]

来源：https://stackoverflow.com/questions/61420933/how-to-store-json-dataframe-with-comma-sepearted