When a Python transformation reads input rows, it converts input port data types to Python data types. When a Python transformation writes output rows, it converts Python data types to output port data types.
For example, the following processing occurs for an input port with the double data type in a Python transformation:
The Python transformation converts the double data type in the input port to the Python float data type.
The transformation uses the value in the input port as the value for the Python float data type.
To generate the output row, the Python transformation converts the Python float data type to the double data type.
The following table shows how the Python transformation maps Developer tool data types to Python data types:
Developer Tool Data Type
Python Data Type
The Python transformation does not support data types that are not listed in this table.
Support for binary ports in the Python transformation is deferred. Support will be reinstated in a future release.
When you write code in the Python transformation, the data types of the output ports in the Python transformation must be compatible with the data types in the Python code. Thus, if you configure an output port in the Python transformation to be a double data type, the corresponding variable in the Python code must be a float.