5.1.1.11. YAML table writer class

class pytablewriter.YamlTableWriter(**kwargs: Any)[source]

Bases: TextTableWriter

A table writer class for YAML format.

Example:

YAML

add_col_separator_style_filter(style_filter: ColSeparatorStyleFilterFunc) None

Add a style filter function for columns to the writer.

Parameters:

style_filter

A function that called for each cell in the table to apply a style to table cells. The function will be required to implement the following Protocol:

class ColSeparatorStyleFilterFunc(Protocol):
    def __call__(
        self, left_cell: Optional[Cell], right_cell: Optional[Cell], **kwargs: Any
    ) -> Optional[Style]:
        ...

If more than one style filter function is added to the writer, it will be called from the last one added. These style functions should return None when not needed to apply styles. If all of the style functions returned None, default_style will be applied.

You can pass keyword arguments to style filter functions via style_filter_kwargs. In default, the attribute includes:

  • writer: the writer instance that the caller of a style_filter function

add_style_filter(style_filter: StyleFilterFunc) None

Add a style filter function to the writer.

Parameters:

style_filter

A function called for each table cell to apply a style to table cells. The function will be required to implement the following Protocol:

class StyleFilterFunc(Protocol):
    def __call__(self, cell: Cell, **kwargs: Any) -> Optional[Style]:
        ...

If more than one style filter function is added to the writer, it will be called from the last one added. These style functions should return None when not needed to apply styles. If all of the style functions returned None, default_style will be used.

You can pass keyword arguments to style filter functions via style_filter_kwargs. In default, the attribute includes:

  • writer: the writer instance that the caller of a style_filter function

clear_theme() None

Remove all of the style filters.

close() None

Close the current stream.

property column_styles: List[Style | None]

Style for each column.

Type:

List[Optional[Style]]

property default_style: Style

Default Style of table cells.

Type:

Style

disable_style_filter(clear_filters: bool = False) None

Disable style filters.

Parameters:

clear_filters (bool) – If True, clear all of the style filters. Defaults to False.

dump(output: str | IO, close_after_write: bool = True, **kwargs: Any) None

Write data to the output with tabular format.

During the executing this method, enable_ansi_escape attribute will be temporarily set to False.

Parameters:
  • output – The value must either an output stream or a path to an output file.

  • close_after_write – Close the output after write. Defaults to True.

dumps(**kwargs: Any) str

Get rendered tabular text from the table data.

Only available for text format table writers.

Parameters:

**kwargs – Optional arguments that the writer takes.

Returns:

Rendered tabular text.

Return type:

str

enable_style_filter() None

Enable style filters.

property format_name: str

Format name for the writer.

Returns:

str

from_csv(csv_source: str, delimiter: str = ',') None

Set tabular attributes to the writer from a character-separated values (CSV) data source. The following attributes are set to the writer by the method:

table_name also be set if the CSV data source is a file. In that case, table_name is as same as the filename.

Parameters:
  • csv_source (str) – Input CSV data source can be designated CSV text or a CSV file path.

  • delimiter (str) – Delimiter character of the CSV data source. Defaults to ,.

Examples

Using CSV as a tabular data source

Dependency Packages:
from_dataframe(dataframe: pandas.DataFrame, add_index_column: bool = False, overwrite_type_hints: bool = True) None

Set tabular attributes to the writer from pandas.DataFrame. The following attributes are set by the method:

Parameters:
  • dataframe (pandas.DataFrame or str) – Input pandas.DataFrame object or path to a DataFrame pickle.

  • add_index_column (bool, optional) – If True, add a column of index of the dataframe. Defaults to False.

  • overwrite_type_hints (bool) – If True, Overwrite type hints with dtypes within the DataFrame.

Example

Using pandas DataFrame as a tabular data source

from_series(series: pandas.Series, add_index_column: bool = True) None

Set tabular attributes to the writer from pandas.Series. The following attributes are set by the method:

Parameters:
  • series (pandas.Series) – Input pandas.Series object.

  • add_index_column (bool, optional) – If True, add a column of index of the series. Defaults to True.

from_tabledata(value: TableData, is_overwrite_table_name: bool = True) None

Set tabular attributes to the writer from TableData. The following attributes are configured:

TableData can be created from various data formats by pytablereader. More detailed information can be found in https://pytablereader.rtfd.io/en/latest/

Parameters:

value (tabledata.TableData) – Input table data.

from_tablib(tablib_dataset: tablib.Dataset) None

Set tabular attributes to the writer from tablib.Dataset.

from_writer(writer: AbstractTableWriter, is_overwrite_table_name: bool = True) None

Copy attributes from another table writer class instance.

Parameters:
  • writer (pytablewriter.writer.AbstractTableWriter) – Another table writer instance.

  • is_overwrite_table_name (bool, optional) – Overwrite the table name of the writer with the table name of the writer. Defaults to True.

property headers: Sequence[str]

Headers of a table to be outputted.

Type:

Sequence[str]

set_style(column: str | int, style: Style) None

Set Style for a specific column.

Parameters:
  • column (int or str) – Column specifier. Column index or header name correlated with the column.

  • style (Style) – Style value to be set to the column.

Raises:

ValueError – Raised when the column specifier is invalid.

set_theme(theme: str, **kwargs: Any) None

Set style filters for a theme.

Parameters:

theme (str) – Name of the theme. pytablewriter theme plugin must be installed corresponding to the theme name.

Raises:

RuntimeError – Raised when a theme plugin does not install.

property support_split_write: bool

Indicates whether the writer class supports iterative table writing (write_table_iter) method.

Returns:

True if the writer supported iterative table writing.

Return type:

bool

property table_format: TableFormat

Get the format of the writer.

Type:

TableFormat

property table_name: str

Name of a table.

Type:

str

property tabledata: TableData

Get tabular data of the writer.

Type:

tabledata.TableData

property type_hints: List[Type[AbstractType] | None]

Type hints for each column of the tabular data. Writers convert data for each column using the type hints information before writing tables when you call write_xxx methods.

Acceptable values are as follows:

  • None (automatically detect column type from values in the column)

  • pytablewriter.typehint.Bool or "bool"

  • pytablewriter.typehint.DateTime or "datetime"

  • pytablewriter.typehint.Dictionary or "dict"

  • pytablewriter.typehint.Infinity or "inf"

  • pytablewriter.typehint.Integer or "int"

  • pytablewriter.typehint.IpAddress or "ipaddr"

  • pytablewriter.typehint.List or "list"

  • pytablewriter.typehint.Nan or "nan"

  • pytablewriter.typehint.NoneType or "none"

  • pytablewriter.typehint.NullString or "nullstr"

  • pytablewriter.typehint.RealNumber or "realnumber" or "float"

  • pytablewriter.typehint.String or "str"

If a type-hint value is not None, the writer tries to convert data for each data in a column to type-hint class. If the type-hint value is None or failed to convert data, the writer automatically detects column data type from the column data.

If type_hints is None, the writer automatically detects data types for all of the columns and writes a table using detected column types.

Defaults to None.

Examples

property value_matrix: Sequence

Data of a table to be outputted.

write_null_line() None

Write a null line to the stream.

write_table(**kwargs: Any) None[source]

Write a table to the stream with YAML format.

Example:

YAML

write_table_iter(**kwargs: Any) None

Write a table with iteration. “Iteration” means that divide the table writing into multiple writes. This method is helpful, especially for extensive data. The following are the premises to execute this method:

  • set iterator to the value_matrix

  • set the number of iterations to the iteration_length attribute

Call back function (Optional): A callback function is called when each iteration of writing a table is completed. You can set a callback function via the write_callback attribute.

Raises:

pytablewriter.NotSupportedError – If the writer class does not support this method.

Note

The following classes do not support this method:

support_split_write attribute return True if the class is supporting this method.