Function read

pyvrp/read.py:39–92

Reads the ``VRPLIB`` file at the given location, and returns a :class:`~pyvrp._pyvrp.ProblemData` instance. .. note:: See the :doc:`VRPLIB format explanation <../dev/supported_vrplib_fields>` page for more details. Parameters ---------- where

(
    where: str | pathlib.Path,
    round_func: str | _RoundingFunc = "none",
)

def read(
    where: str | pathlib.Path,
    round_func: str | _RoundingFunc = "none",
) -> ProblemData:
    """
    Reads the ``VRPLIB`` file at the given location, and returns a
    :class:`~pyvrp._pyvrp.ProblemData` instance.

    .. note::

       See the
       :doc:`VRPLIB format explanation <../dev/supported_vrplib_fields>` page
       for more details.

    Parameters
    ----------
    where
        File location to read. Assumes the data on the given location is in
        ``VRPLIB`` format.
    round_func
        Optional rounding function that is applied to all data values in the
        instance. This can either be a function or a string:

            * ``'round'`` rounds the values to the nearest integer;
            * ``'trunc'`` truncates the values to an integer;
            * ``'dimacs'`` scales by 10 and truncates the values to an integer;
            * ``'exact'`` scales by 1000 and rounds to the nearest integer.
            * ``'none'`` does no rounding. This is the default.

    Raises
    ------
    TypeError
        When ``round_func`` does not name a rounding function, or is not
        callable.
    ValueError
        When the data file does not provide information on the problem size.

    Returns
    -------
    ProblemData
        Data instance constructed from the read data.
    """
    if (key := str(round_func)) in ROUND_FUNCS:
        round_func = ROUND_FUNCS[key]

    if not callable(round_func):
        raise TypeError(
            f"round_func = {round_func} is not understood. Can be a function,"
            f" or one of {ROUND_FUNCS.keys()}."
        )

    parser = _InstanceParser(vrplib.read_instance(where), round_func)
    builder = _ProblemDataBuilder(parser)
    return builder.data()


def read_solution(where: str | pathlib.Path, data: ProblemData) -> Solution: