I would like append a new column on dataframe \"df\" from function get_distance:
def get_distance(x, y):
Spark should know the function that you are using is not ordinary function but the UDF.
So, there are 2 ways by which we can use the UDF on dataframes.
Method-1: With @udf annotation
@udf
def get_distance(x, y):
dfDistPerc = hiveContext.sql("select column3 as column3, \
from tab \
where column1 = '" + x + "' \
and column2 = " + y + " \
limit 1")
result = dfDistPerc.select("column3").take(1)
return result
df = df.withColumn(
"distance",
lit(get_distance(df["column1"], df["column2"]))
)
Method-2: Regestering udf with pyspark.sql.functions.udf
def get_distance(x, y):
dfDistPerc = hiveContext.sql("select column3 as column3, \
from tab \
where column1 = '" + x + "' \
and column2 = " + y + " \
limit 1")
result = dfDistPerc.select("column3").take(1)
return result
calculate_distance_udf = udf(get_distance, IntegerType())
df = df.withColumn(
"distance",
lit(calculate_distance_udf(df["column1"], df["column2"]))
)