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Schema

Bases: ABC

The schema of a row or table.

Source code in src/safeds/data/tabular/typing/_schema.py 
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class Schema(ABC):
    """The schema of a row or table."""

    # ------------------------------------------------------------------------------------------------------------------
    # Dunder methods
    # ------------------------------------------------------------------------------------------------------------------

    @abstractmethod
    def __eq__(self, other: object) -> bool: ...

    @abstractmethod
    def __hash__(self) -> int: ...

    @abstractmethod
    def __repr__(self) -> str: ...

    @abstractmethod
    def __sizeof__(self) -> int: ...

    @abstractmethod
    def __str__(self) -> str: ...

    # ------------------------------------------------------------------------------------------------------------------
    # Properties
    # ------------------------------------------------------------------------------------------------------------------

    @property
    @abstractmethod
    def column_names(self) -> list[str]:
        """
        Return a list of all column names contained in this schema.

        Returns
        -------
        column_names:
            The column names.

        Examples
        --------
        >>> from safeds.data.tabular.containers import Table
        >>> table = Table({"A": [1, 2, 3], "B": ["a", "b", "c"]})
        >>> table.schema.column_names
        ['A', 'B']
        """

    # ------------------------------------------------------------------------------------------------------------------
    # Getters
    # ------------------------------------------------------------------------------------------------------------------

    @abstractmethod
    def get_column_type(self, name: str) -> DataType:
        """
        Return the type of the given column.

        Parameters
        ----------
        name:
            The name of the column.

        Returns
        -------
        type:
            The type of the column.

        Raises
        ------
        ColumnNotFoundError
            If the specified column name does not exist.

        Examples
        --------
        >>> from safeds.data.tabular.containers import Table
        >>> table = Table({"A": [1, 2, 3], "B": ["a", "b", "c"]})
        >>> type_ = table.schema.get_column_type("A")
        """

    @abstractmethod
    def has_column(self, name: str) -> bool:
        """
        Return whether the schema contains a given column.

        Parameters
        ----------
        name:
            The name of the column.

        Returns
        -------
        contains:
            True if the schema contains the column.

        Examples
        --------
        >>> from safeds.data.tabular.containers import Table
        >>> table = Table({"A": [1, 2, 3], "B": ["a", "b", "c"]})
        >>> table.schema.has_column("A")
        True

        >>> table.schema.has_column("C")
        False
        """

    # ------------------------------------------------------------------------------------------------------------------
    # Conversion
    # ------------------------------------------------------------------------------------------------------------------

    @abstractmethod
    def to_dict(self) -> dict[str, DataType]:
        """
        Return a dictionary that maps column names to column types.

        Returns
        -------
        data:
            Dictionary representation of the schema.

        Examples
        --------
        >>> from safeds.data.tabular.containers import Table
        >>> table = Table({"A": [1, 2, 3], "B": ["a", "b", "c"]})
        >>> dict_ = table.schema.to_dict()
        """

    # ------------------------------------------------------------------------------------------------------------------
    # IPython integration
    # ------------------------------------------------------------------------------------------------------------------

    @abstractmethod
    def _repr_markdown_(self) -> str:
        """
        Return a Markdown representation of the schema for IPython.

        Returns
        -------
        markdown:
            The generated Markdown.
        """

column_names: list[str]

Return a list of all column names contained in this schema.

Returns:

Name Type Description
column_names list[str]

The column names.

Examples:

>>> from safeds.data.tabular.containers import Table
>>> table = Table({"A": [1, 2, 3], "B": ["a", "b", "c"]})
>>> table.schema.column_names
['A', 'B']

get_column_type

Return the type of the given column.

Parameters:

Name Type Description Default
name str

The name of the column.

 required

Returns:

Name Type Description
type DataType

The type of the column.

Raises:

Type Description
ColumnNotFoundError

If the specified column name does not exist.

Examples:

>>> from safeds.data.tabular.containers import Table
>>> table = Table({"A": [1, 2, 3], "B": ["a", "b", "c"]})
>>> type_ = table.schema.get_column_type("A")
Source code in src/safeds/data/tabular/typing/_schema.py 
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@abstractmethod
def get_column_type(self, name: str) -> DataType:
    """
    Return the type of the given column.

    Parameters
    ----------
    name:
        The name of the column.

    Returns
    -------
    type:
        The type of the column.

    Raises
    ------
    ColumnNotFoundError
        If the specified column name does not exist.

    Examples
    --------
    >>> from safeds.data.tabular.containers import Table
    >>> table = Table({"A": [1, 2, 3], "B": ["a", "b", "c"]})
    >>> type_ = table.schema.get_column_type("A")
    """

has_column

Return whether the schema contains a given column.

Parameters:

Name Type Description Default
name str

The name of the column.

 required

Returns:

Name Type Description
contains bool

True if the schema contains the column.

Examples:

>>> from safeds.data.tabular.containers import Table
>>> table = Table({"A": [1, 2, 3], "B": ["a", "b", "c"]})
>>> table.schema.has_column("A")
True

>>> table.schema.has_column("C")
False
Source code in src/safeds/data/tabular/typing/_schema.py 
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@abstractmethod
def has_column(self, name: str) -> bool:
    """
    Return whether the schema contains a given column.

    Parameters
    ----------
    name:
        The name of the column.

    Returns
    -------
    contains:
        True if the schema contains the column.

    Examples
    --------
    >>> from safeds.data.tabular.containers import Table
    >>> table = Table({"A": [1, 2, 3], "B": ["a", "b", "c"]})
    >>> table.schema.has_column("A")
    True

    >>> table.schema.has_column("C")
    False
    """

to_dict

Return a dictionary that maps column names to column types.

Returns:

Name Type Description
data dict[str, DataType]

Dictionary representation of the schema.

Examples:

>>> from safeds.data.tabular.containers import Table
>>> table = Table({"A": [1, 2, 3], "B": ["a", "b", "c"]})
>>> dict_ = table.schema.to_dict()
Source code in src/safeds/data/tabular/typing/_schema.py 
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@abstractmethod
def to_dict(self) -> dict[str, DataType]:
    """
    Return a dictionary that maps column names to column types.

    Returns
    -------
    data:
        Dictionary representation of the schema.

    Examples
    --------
    >>> from safeds.data.tabular.containers import Table
    >>> table = Table({"A": [1, 2, 3], "B": ["a", "b", "c"]})
    >>> dict_ = table.schema.to_dict()
    """