Table of Contents

Search

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

0 COMMENTS

We’d like to hear from you!