Table of Contents

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  1. Preface
  2. Transformations
  3. Source transformation
  4. Target transformation
  5. Access Policy transformation
  6. B2B transformation
  7. Aggregator transformation
  8. Cleanse transformation
  9. Data Masking transformation
  10. Data Services transformation
  11. Deduplicate transformation
  12. Expression transformation
  13. Filter transformation
  14. Hierarchy Builder transformation
  15. Hierarchy Parser transformation
  16. Hierarchy Processor transformation
  17. Input transformation
  18. Java transformation
  19. Java transformation API reference
  20. Joiner transformation
  21. Labeler transformation
  22. Lookup transformation
  23. Machine Learning transformation
  24. Mapplet transformation
  25. Normalizer transformation
  26. Output transformation
  27. Parse transformation
  28. Python transformation
  29. Rank transformation
  30. Router transformation
  31. Rule Specification transformation
  32. Sequence Generator transformation
  33. Sorter transformation
  34. SQL transformation
  35. Structure Parser transformation
  36. Transaction Control transformation
  37. Union transformation
  38. Velocity transformation
  39. Verifier transformation
  40. Web Services transformation

Transformations

Transformations

Developing the Python code

Developing the Python code

To define the Python transformation functionality, you enter Python code snippets on the
Python
tab. Enter code snippets to reconstruct input variables, load a pre-trained model, define output variables, and define additional transformation functionality.
Enter Python code snippets in the following sections of the Python editor:
Pre-Partition Python Code
Defines code that can be interpreted one time and shared among all rows of data.
Use the
Pre-Partition Python Code
section to perform the following tasks:
  • Declare import statements.
  • Declare variables.
  • Initialize variables.
  • Define helper methods.
Main Python Code
Defines how the Python transformation behaves when it receives an input row while processing a partition. The Python transformation processes the code on the
Main Python Code
section for each partition and each row.
Post-Partition Python Code
Defines how the Python transformation behaves after it processes all input data in a partition. You can call the
generateRow()
method to generate output rows.
Use the following guidelines when you write Python code:
  • Define variables before you use them. For example, you cannot reference a variable in the
    Pre-Partition Python Code
    section if the variable is defined in the
    Main Python Code
    section.
  • Call the incoming field name to access incoming fields.
  • The Python code must assign a value to each output field.
  • To define how the transformation writes data from the incoming fields to output fields, set the output field to the value of the incoming field.
    For example, write
    output_field = incoming_field
    to write the data from the incoming field
    incoming_field
    to the output field
    output_field
    .
  • To access resource files, use the variable
    resourceFilesArray
    . Specify the resource file using an index such as
    resourceFilesArray[0]
    .
  • The Mapping Designer does not validate Python code.

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