Skip to main content

flat_map()

Creates a flat-map node with optional configuration to the pipeline. This node calls the specified function to create a list matching the output schema from the one matching the input schema and flattens the output list.

flat_map(input_schema, output_schema, fn, config=None)

Parameters​

  • input_schema - str or tuple[str]

    • A column name or all column names of the input list

    • Each column name in the schema should be a string, containing alphanumerical characters and underscores.

  • output_schema - str or tuple[str]

    • A column name or all column names of the output list

    • Each column name in the schema should be a string, containing alphanumerical characters and underscores.

  • fn - Operator, lambda, or callable

    • A function that is used to map an item in the input list into an item in the output list.

    • It can be an operator from Towhee Hub, a lambda, or a callable function.

  • config - dict or None

    • Optional configuration for the current node.

    • It defaults to None and can be a dictionary containing the configuration items. See AutoConfig API for details.

Returns​

A not-callable Pipeline object with this flat-map node appended

Example​

from towhee import pipe, ops

p = (pipe.input('a')
         .flat_map('a', 'b', lambda x: [e+10 for e in x])
         .output('b'))
res = p([1,2,3])
res.to_list() # return [[11], [12], [13]]