CODEWITHSUNDEEP
apache-sparkpysparkapache-spark-sqlnull
milton
milton

Reputation: 111

pyspark can't stop reading empty string as null (spark 3.0)

I have a some csv data file like this (^ as delmiter):

ID name age
0
1 Mike 20

When I do

df = spark.read.option("delimiter", "^").option("quote","").option("header", "true").option(
        "inferSchema", "true").csv(xxxxxxx)

spark will default the 2 column after 0 row to null

df.show():
ID name age
0 null null
1 Mike 20

How can I stop pyspark to read the data as null but just empty string?

I have tried add some option in the end

1,option("nullValue", "xxxx").option("treatEmptyValuesAsNulls", False)
2,option("nullValue", None).option("treatEmptyValuesAsNulls", False)
3,option("nullValue", None).option("emptyValue", None)
4,option("nullValue", "xxx").option("emptyValue", "xxx")

But no matter what I do pyspark is still reading the data as null.. Is there a way to make pyspark read the empty string as it is?

Thanks

Upvotes: 0

Views: 1619

Answers (1)

Kafels
Kafels

Reputation: 4069

It looks that the empty values since Spark Version 2.0.1 are treated as null. A manner to achieve your result is using df.na.fill(...):

df = spark.read.csv('your_data_path', sep='^', header=True)
# root
#  |-- ID: string (nullable = true)
#  |-- name: string (nullable = true)
#  |-- age: string (nullable = true)

# Fill all columns
# df = df.na.fill('')

# Fill specific columns
df = df.na.fill('', subset=['name', 'age'])

df.show(truncate=False)

Output

+---+----+---+
|ID |name|age|
+---+----+---+
|0  |    |   |
|1  |Mike|20 |
+---+----+---+

Upvotes: 2

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