Exploder¶
-
class
Exploder
(path_to_array='included', exploded_elem_name='elem')[source]¶ Bases:
spooq2.transformer.transformer.Transformer
Explodes an array within a DataFrame and drops the column containing the source array.
Examples
>>> transformer = Exploder( >>> path_to_array="attributes.friends", >>> exploded_elem_name="friend", >>> )
Parameters: - path_to_array (
str
, (Defaults to ‘included’)) – Defines the Column Name / Path to the Array. Dropping nested columns is not supported. Although, you can still explode them. - exploded_elem_name (
str
, (Defaults to ‘elem’)) – Defines the column name the exploded column will get. This is important to know how to access the Field afterwards. Writing nested columns is not supported. The output column has to be first level.
Warning
Support for nested column:
- path_to_array:
- PySpark cannot drop a field within a struct. This means the specific field can be referenced and therefore exploded, but not dropped.
- exploded_elem_name:
- If you (re)name a column in the dot notation, is creates a first level column, just with a dot its name. To create a struct with the column as a field you have to redefine the structure or use a UDF.
Note
The
explode()
method of Spark is used internally.Note
The size of the resulting DataFrame is not guaranteed to be equal to the Input DataFrame!
-
transform
(input_df)[source]¶ Performs a transformation on a DataFrame.
Parameters: input_df ( pyspark.sql.DataFrame
) – Input DataFrameReturns: Transformed DataFrame. Return type: pyspark.sql.DataFrame
Note
This method does only take the Input DataFrame as a parameters. All other needed parameters are defined in the initialization of the Transformator Object.
- path_to_array (