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window()

Creates a window node with optional configuration to the pipeline. This node iterates over the input list at the specified step size. Within each iteration, this node creates a window of the specified size in the input list, calls the function on the items in the window, and appends the result of the function to the output list.

window(input_schema, output_schema, size, step, 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.

  • size - int

    • Size of the window to be created within each iteration.

  • step - int

    • Step size of the iteration over the input list.

  • fn - Operator, lambda, or callable

    • A function with the items in the current window as the input.

    • 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 window node appended

Example​

from towhee import pipe

p = (pipe.input('n1', 'n2')
        .flat_map(('n1', 'n2'), ('n1', 'n2'), lambda x, y: [(a, b) for a, b in zip(x, y)])
        .window(('n1', 'n2'), ('s1', 's2'), 2, 1, lambda x, y: (sum(x), sum(y)))
        .output('s1', 's2'))
res = p([1, 2, 3, 4], [2, 3, 4, 5])
res.to_list() # return [[3, 5], [5, 7], [7, 9], [4, 5]]