User-Defined Table Functions¶

User-defined table functions (UDTFs) in Snowpark. Please see Python UDTF for details. There is also vectorized UDTF. Compared to the default row-by-row processing pattern of a normal UDTF, which sometimes is inefficient, vectorized Python UDTFs (user-defined table functions) enable seamless partition-by-partition processing by operating on partitions as pandas DataFrames (https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.html) and returning results as pandas DataFrames (https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.html) or lists of pandas arrays (https://pandas.pydata.org/docs/reference/api/pandas.array.html) or pandas Series (https://pandas.pydata.org/docs/reference/series.html).

In addition, vectorized Python UDTFs allow for easy integration with libraries that operate on pandas DataFrames or pandas arrays.

A vectorized UDTF handler class:

defines an end_partition method that takes in a DataFrame argument and returns a pandas.DataFrame or a tuple of pandas.Series or pandas.arrays where each array is a column.
does NOT define a process method.
optionally defines a handler class with an __init__ method which will be invoked before processing each partition.

Note

A vectorized UDTF must be called with partition_by() to build the partitions.

Refer to UDTFRegistration for details and sample code on how to create regular and vectorized UDTFs using Snowpark Python API.

Classes

`UDTFRegistration`(session)	Provides methods to register classes as UDTFs in the Snowflake database.
`UserDefinedTableFunction`(handler, ...[, ...])	Encapsulates a user defined table function that is returned by `udtf()`, `UDTFRegistration.register()` or `UDTFRegistration.register_from_file()`.

Methods

`register`(handler, output_schema[, ...])	Registers a Python class as a Snowflake Python UDTF and returns the UDTF.
`register_from_file`(file_path, handler_name, ...)	Registers a Python class as a Snowflake Python UDTF from a Python or zip file, and returns the UDTF.

Attributes

`handler`	The Python class or a tuple containing the Python file path and the function name.
`name`	The UDTF name.