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# Source code for astropy.table.row

    # Licensed under a 3-clause BSD style license - see LICENSE.rst

    import collections
    from collections import OrderedDict
    from operator import index as operator_index

    import numpy as np

    class Row:
        """A class to represent one row of a Table object.

        A Row object is returned when a Table object is indexed with an integer
        or when iterating over a table::

          >>> from astropy.table import Table
          >>> table = Table([(1, 2), (3, 4)], names=('a', 'b'),
          ...               dtype=('int32', 'int32'))
          >>> row = table[1]
          >>> row
          <Row index=1>
            a     b
          int32 int32
          ----- -----
              2     4
          >>> row['a']
          np.int32(2)
          >>> row[1]
          np.int32(4)
        """

        def __init__(self, table, index):
            # Ensure that the row index is a valid index (int)
            index = operator_index(index)

            n = len(table)

            if index < -n or index >= n:
                raise IndexError(
                    f"index {index} out of range for table with length {len(table)}"
                )

            # Finally, ensure the index is positive [#8422] and set Row attributes
            self._index = index % n
            self._table = table

        def __getitem__(self, item):
            try:
                # Try the most common use case of accessing a single column in the Row.
                # Bypass the TableColumns __getitem__ since that does more testing
                # and allows a list of tuple or str, which is not the right thing here.
                out = OrderedDict.__getitem__(self._table.columns, item)[self._index]
            except (KeyError, TypeError):
                if self._table._is_list_or_tuple_of_str(item):
                    cols = [self._table[name] for name in item]
                    out = self._table.__class__(cols, copy=False)[self._index]
                elif isinstance(item, slice):
                    # https://github.com/astropy/astropy/issues/14007
                    out = tuple(self.values())[item]
                else:
                    # This is only to raise an exception
                    out = self._table.columns[item][self._index]
            return out

        def __setitem__(self, item, val):
            if self._table._is_list_or_tuple_of_str(item):
                self._table._set_row(self._index, colnames=item, vals=val)
            else:
                self._table.columns[item][self._index] = val

        def _ipython_key_completions_(self):
            return self.colnames

        def __eq__(self, other):
            if self._table.masked:
                # Sent bug report to numpy-discussion group on 2012-Oct-21, subject:
                # "Comparing rows in a structured masked array raises exception"
                # No response, so this is still unresolved.
                raise ValueError(
                    "Unable to compare rows for masked table due to numpy.ma bug"
                )
            return self.as_void() == other

        def __ne__(self, other):
            if self._table.masked:
                raise ValueError(
                    "Unable to compare rows for masked table due to numpy.ma bug"
                )
            return self.as_void() != other

        def __array__(self, dtype=None, copy=None):
            """Support converting Row to np.array via np.array(table).

            Coercion to a different dtype via np.array(table, dtype) is not
            supported and will raise a ValueError.

            If the parent table is masked then the mask information is dropped.
            """
            if dtype is not None:
                raise ValueError("Datatype coercion is not allowed")

            return np.array(self.as_void(), copy=copy)

        def __len__(self):
            return len(self._table.columns)

        def __iter__(self):
            index = self._index
            for col in self._table.columns.values():
                yield col[index]

        def get(self, key, default=None, /):
            """Return the value for key if key is in the columns, else default.

            Parameters
            ----------
            key : `str`, positional-only
                The name of the column to look for.
            default : `object`, optional, positional-only
                The value to return if the ``key`` is not among the columns.

            Returns
            -------
            `object`
                The value in the ``key`` column of the row if present,
                ``default`` otherwise.

            Examples
            --------
            >>> from astropy.table import Table
            >>> t = Table({"a": [2., 3., 5.], "b": [7., 11., 13.]})
            >>> t[0].get("a")
            np.float64(2.0)
            >>> t[1].get("b", 0.)
            np.float64(11.0)
            >>> t[2].get("c", 0.)
            0.0
            """
            return self[key] if key in self._table.columns else default

        def keys(self):
            return self._table.columns.keys()

        def values(self):
            return self.__iter__()

        @property
        def table(self):
            return self._table

        @property
        def index(self):
            return self._index

        def as_void(self):
            """
            Returns a *read-only* copy of the row values in the form of np.void or
            np.ma.mvoid objects.  This corresponds to the object types returned for
            row indexing of a pure numpy structured array or masked array. This
            method is slow and its use is discouraged when possible.

            Returns
            -------
            void_row : ``numpy.void`` or ``numpy.ma.mvoid``
                Copy of row values.
                ``numpy.void`` if unmasked, ``numpy.ma.mvoid`` else.
            """
            index = self._index
            cols = self._table.columns.values()
            vals = tuple(np.asarray(col)[index] for col in cols)
            if self._table.masked:
                mask = tuple(
                    col.mask[index] if hasattr(col, "mask") else False for col in cols
                )
                void_row = np.ma.array([vals], mask=[mask], dtype=self.dtype)[0]
            else:
                void_row = np.array([vals], dtype=self.dtype)[0]
            return void_row

        @property
        def meta(self):
            return self._table.meta

        @property
        def columns(self):
            return self._table.columns

        @property
        def colnames(self):
            return self._table.colnames

        @property
        def dtype(self):
            return self._table.dtype

        def _base_repr_(self, html=False):
            """
            Display row as a single-line table but with appropriate header line.
            """
            index = self.index if (self.index >= 0) else self.index + len(self._table)
            table = self._table[index : index + 1]
            descr_vals = [self.__class__.__name__, f"index={self.index}"]
            if table.masked:
                descr_vals.append("masked=True")

            return table._base_repr_(
                html, descr_vals, max_width=-1, tableid=f"table{id(self._table)}"
            )

        def _repr_html_(self):
            return self._base_repr_(html=True)

        def __repr__(self):
            return self._base_repr_(html=False)

        def __str__(self):
            index = self.index if (self.index >= 0) else self.index + len(self._table)
            return "\n".join(self.table[index : index + 1].pformat(max_width=-1))

        def __bytes__(self):
            return str(self).encode("utf-8")

    collections.abc.Sequence.register(Row)