python/pyspark/resultiterable.py

#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
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# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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from typing import TypeVar, TYPE_CHECKING, Iterator, Iterable

if TYPE_CHECKING:
    from pyspark._typing import SizedIterable


__all__ = ["ResultIterable"]

T = TypeVar("T")


class ResultIterable(Iterable[T]):

    """
    A special result iterable. This is used because the standard
    iterator can not be pickled
    """

    def __init__(self, data: "SizedIterable[T]"):
        self.data: "SizedIterable[T]" = data
        self.index: int = 0
        self.maxindex: int = len(data)

    def __iter__(self) -> Iterator[T]:
        return iter(self.data)

    def __len__(self) -> int:
        return len(self.data)