#Pyspark fhash code#

We often need to check with multiple conditions, below is an example of using PySpark When Otherwise with multiple conditions by using and (&) or (|) operators. Multiple Conditions using & and | operator 'ELSE gender END as new_gender from EMP').show()Ģ.3. Spark.sql('select name, CASE WHEN gender = 'M' THEN 'Male' ' + You can also use Case When with SQL statement after creating a temporary view. 'WHEN gender = 'F' THEN 'Female' WHEN gender IS NULL THEN ''' +ĭf4 = df.select(col('*'), expr('CASE WHEN gender = 'M' THEN 'Male' ' + If none of the condition matches, it returns a value from the ELSE clause.Ģ.1 Using Case When Else on DataFrame using withColumn() & select()īelow example uses PySpark SQL expr() Function to express SQL like expressions.įrom import expr, colĭf3 = df.withColumn('new_gender', expr('CASE WHEN gender = 'M' THEN 'Male' ' +.If the condition is false it goes to the next condition and so on.

Clause WHEN takes a condition, if condition true it returns a value from THEN.

Similarly, PySpark SQL Case When statement can be used on DataFrame, below are some of the examples of using with withColumn(), select(), selectExpr() utilizing expr() function. If you have a SQL background you might have familiar with Case When statement that is used to execute a sequence of conditions and returns a value when the first condition met, similar to SWITH and IF THEN ELSE statements.

#Pyspark fhash code#

The below code snippet replaces the value of gender with a new derived value, when conditions not matched, we are assigning “Unknown” as value, for null assigning empty.ĭf2 = df.withColumn('new_gender', when(df.gender = 'M','Male')ĭf2=df.select(col('*'),when(df.gender = 'M','Male') When() function take 2 parameters, first param takes a condition and second takes a literal value or Column, if condition evaluates to true then it returns a value from second param. Usage would be like when(condition).otherwise(default). PySpark when() is SQL function, in order to use this first you should import and this returns a Column type, otherwise() is a function of Column, when otherwise() not used and none of the conditions met it assigns None (Null) value. Using w hen() o therwise() on PySpark D ataFrame.