Passing Array to Python Spark Lit Function

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南笙
南笙 2021-02-18 16:48

Let\'s say I have a numpy array a that contains the numbers 1-10. So a is [1 2 3 4 5 6 7 8 9 10].

Now, I also have a Python Spark dataframe to which I want to add my num

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  •  心在旅途
    2021-02-18 17:09

    for loop in array inbuilt function

    You can use array inbuilt function as

    a = [1,2,3,4,5,6,7,8,9,10]
    df = spark.createDataFrame([['a b c d e f g h i j '],], ['col1'])
    df = df.withColumn("NewColumn", F.array([F.lit(x) for x in a]))
    df.show(truncate=False)
    

    You should get

    +--------------------+-------------------------------+
    |col1                |NewColumn                      |
    +--------------------+-------------------------------+
    |a b c d e f g h i j |[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]|
    +--------------------+-------------------------------+
    root
     |-- col1: string (nullable = true)
     |-- NewColumn: array (nullable = false)
     |    |-- element: integer (containsNull = false)
    

    Using udf function

    #udf function
    def arrayUdf():
        return a
    callArrayUdf = F.udf(arrayUdf, T.ArrayType(T.IntegerType()))
    
    #calling udf function
    df = df.withColumn("NewColumn", callArrayUdf())
    

    output is same as with for loop way

    Updated

    I am pasting @pault's comment given below

    You can hide the loop using map: df.withColumn("NewColumn", F.array(map(F.lit, a)))

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