# Source code for MDAnalysis.exceptions

    # -*- Mode: python; tab-width: 4; indent-tabs-mode:nil; coding:utf-8 -*-
    # vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4
    #
    # MDAnalysis --- https://www.mdanalysis.org
    # Copyright (c) 2006-2017 The MDAnalysis Development Team and contributors
    # (see the file AUTHORS for the full list of names)
    #
    # Released under the Lesser GNU Public Licence, v2.1 or any higher version
    #
    # Please cite your use of MDAnalysis in published work:
    #
    # R. J. Gowers, M. Linke, J. Barnoud, T. J. E. Reddy, M. N. Melo, S. L. Seyler,
    # D. L. Dotson, J. Domanski, S. Buchoux, I. M. Kenney, and O. Beckstein.
    # MDAnalysis: A Python package for the rapid analysis of molecular dynamics
    # simulations. In S. Benthall and S. Rostrup editors, Proceedings of the 15th
    # Python in Science Conference, pages 102-109, Austin, TX, 2016. SciPy.
    # doi: 10.25080/majora-629e541a-00e
    #
    # N. Michaud-Agrawal, E. J. Denning, T. B. Woolf, and O. Beckstein.
    # MDAnalysis: A Toolkit for the Analysis of Molecular Dynamics Simulations.
    # J. Comput. Chem. 32 (2011), 2319--2327, doi:10.1002/jcc.21787
    #

    """
    Custom exceptions and warnings --- :mod:`MDAnalysis.exceptions`
    ===============================================================

    """

    class SelectionError(Exception):
        """Raised when a atom selection failed."""

    class NoDataError(ValueError, AttributeError):
        """Raised when empty input is not allowed or required data are missing.

        This exception is raised in the following scenarios:

        * Raised when a :class:`~MDAnalysis.core.topologyattrs.TopologyAttr`
          (e.g., bonds, charges) is not present in the data.

        * Raised when data is missing in an analysis class because the `run()`
          method has not been called, e.g.
          :class:`~MDAnalysis.analysis.polymer.PersistenceLength`.

        * Raised when timestep data is missing, such as positions, velocities,
          or forces.

        * Raised in the `nojump` transformation if there is no box information
          in the universe.

        This exception should not be raised in cases where arrays have zero width,
        or AtomGroups are empty.

        .. versionchanged:: 1.0.0
            Now a subclass of AttributeError as well as ValueError
        """

    class ApplicationError(OSError):
        """Raised when an external application failed.

        The error code is specific for the application.

        .. versionadded:: 0.7.7
        """

    class SelectionWarning(Warning):
        """Warning indicating a possible problem with a selection."""

    class MissingDataWarning(Warning):
        """Warning indicating is that required data are missing."""

    class ConversionWarning(Warning):
        """Warning indicating a problem with converting between units."""

    class FileFormatWarning(Warning):
        """Warning indicating possible problems with a file format."""

    class StreamWarning(Warning):
        """Warning indicating a possible problem with a stream.

        :exc:`StreamWarning` is used when streams are substituted for simple access
        by filename (see in particular
        :class:`~MDAnalysis.lib.util.NamedStream`). This does not work everywhere
        in MDAnalysis (yet).
        """

    class DuplicateWarning(UserWarning):
        """Warning indicating possible problems arising from an
        :class:`~MDAnalysis.core.groups.AtomGroup` /
        :class:`~MDAnalysis.core.groups.ResidueGroup` /
        :class:`~MDAnalysis.core.groups.SegmentGroup` containing duplicate
        :class:`Atoms<MDAnalysis.core.groups.Atom>` /
        :class:`Residues<MDAnalysis.core.groups.Residue>` /
        :class:`Segments<MDAnalysis.core.groups.Segment>`.

        .. versionadded:: 0.19.0
        """