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Diffstat (limited to 'cli_helpers/tabular_output/preprocessors.py')
| -rw-r--r-- | cli_helpers/tabular_output/preprocessors.py | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/cli_helpers/tabular_output/preprocessors.py b/cli_helpers/tabular_output/preprocessors.py new file mode 100644 index 0000000..d6d09e0 --- /dev/null +++ b/cli_helpers/tabular_output/preprocessors.py @@ -0,0 +1,300 @@ +# -*- coding: utf-8 -*- +"""These preprocessor functions are used to process data prior to output.""" + +import string + +from cli_helpers import utils +from cli_helpers.compat import text_type, int_types, float_types, HAS_PYGMENTS + + +def truncate_string(data, headers, max_field_width=None, skip_multiline_string=True, **_): + """Truncate very long strings. Only needed for tabular + representation, because trying to tabulate very long data + is problematic in terms of performance, and does not make any + sense visually. + + :param iterable data: An :term:`iterable` (e.g. list) of rows. + :param iterable headers: The column headers. + :param int max_field_width: Width to truncate field for display + :return: The processed data and headers. + :rtype: tuple + """ + return (([utils.truncate_string(v, max_field_width, skip_multiline_string) for v in row] for row in data), + [utils.truncate_string(h, max_field_width, skip_multiline_string) for h in headers]) + + +def convert_to_string(data, headers, **_): + """Convert all *data* and *headers* to strings. + + Binary data that cannot be decoded is converted to a hexadecimal + representation via :func:`binascii.hexlify`. + + :param iterable data: An :term:`iterable` (e.g. list) of rows. + :param iterable headers: The column headers. + :return: The processed data and headers. + :rtype: tuple + + """ + return (([utils.to_string(v) for v in row] for row in data), + [utils.to_string(h) for h in headers]) + + +def override_missing_value(data, headers, style=None, + missing_value_token="Token.Output.Null", + missing_value='', **_): + """Override missing values in the *data* with *missing_value*. + + A missing value is any value that is :data:`None`. + + :param iterable data: An :term:`iterable` (e.g. list) of rows. + :param iterable headers: The column headers. + :param style: Style for missing_value. + :param missing_value_token: The Pygments token used for missing data. + :param missing_value: The default value to use for missing data. + :return: The processed data and headers. + :rtype: tuple + + """ + def fields(): + for row in data: + processed = [] + for field in row: + if field is None and style and HAS_PYGMENTS: + styled = utils.style_field(missing_value_token, missing_value, style) + processed.append(styled) + elif field is None: + processed.append(missing_value) + else: + processed.append(field) + yield processed + + return (fields(), headers) + + +def override_tab_value(data, headers, new_value=' ', **_): + """Override tab values in the *data* with *new_value*. + + :param iterable data: An :term:`iterable` (e.g. list) of rows. + :param iterable headers: The column headers. + :param new_value: The new value to use for tab. + :return: The processed data and headers. + :rtype: tuple + + """ + return (([v.replace('\t', new_value) if isinstance(v, text_type) else v + for v in row] for row in data), + headers) + + +def escape_newlines(data, headers, **_): + """Escape newline characters (\n -> \\n, \r -> \\r) + + :param iterable data: An :term:`iterable` (e.g. list) of rows. + :param iterable headers: The column headers. + :return: The processed data and headers. + :rtype: tuple + + """ + return ( + ( + [ + v.replace("\r", r"\r").replace("\n", r"\n") + if isinstance(v, text_type) + else v + for v in row + ] + for row in data + ), + headers, + ) + + +def bytes_to_string(data, headers, **_): + """Convert all *data* and *headers* bytes to strings. + + Binary data that cannot be decoded is converted to a hexadecimal + representation via :func:`binascii.hexlify`. + + :param iterable data: An :term:`iterable` (e.g. list) of rows. + :param iterable headers: The column headers. + :return: The processed data and headers. + :rtype: tuple + + """ + return (([utils.bytes_to_string(v) for v in row] for row in data), + [utils.bytes_to_string(h) for h in headers]) + + +def align_decimals(data, headers, column_types=(), **_): + """Align numbers in *data* on their decimal points. + + Whitespace padding is added before a number so that all numbers in a + column are aligned. + + Outputting data before aligning the decimals:: + + 1 + 2.1 + 10.59 + + Outputting data after aligning the decimals:: + + 1 + 2.1 + 10.59 + + :param iterable data: An :term:`iterable` (e.g. list) of rows. + :param iterable headers: The column headers. + :param iterable column_types: The columns' type objects (e.g. int or float). + :return: The processed data and headers. + :rtype: tuple + + """ + pointpos = len(headers) * [0] + data = list(data) + for row in data: + for i, v in enumerate(row): + if column_types[i] is float and type(v) in float_types: + v = text_type(v) + pointpos[i] = max(utils.intlen(v), pointpos[i]) + + def results(data): + for row in data: + result = [] + for i, v in enumerate(row): + if column_types[i] is float and type(v) in float_types: + v = text_type(v) + result.append((pointpos[i] - utils.intlen(v)) * " " + v) + else: + result.append(v) + yield result + + return results(data), headers + + +def quote_whitespaces(data, headers, quotestyle="'", **_): + """Quote leading/trailing whitespace in *data*. + + When outputing data with leading or trailing whitespace, it can be useful + to put quotation marks around the value so the whitespace is more + apparent. If one value in a column needs quoted, then all values in that + column are quoted to keep things consistent. + + .. NOTE:: + :data:`string.whitespace` is used to determine which characters are + whitespace. + + :param iterable data: An :term:`iterable` (e.g. list) of rows. + :param iterable headers: The column headers. + :param str quotestyle: The quotation mark to use (defaults to ``'``). + :return: The processed data and headers. + :rtype: tuple + + """ + whitespace = tuple(string.whitespace) + quote = len(headers) * [False] + data = list(data) + for row in data: + for i, v in enumerate(row): + v = text_type(v) + if v.startswith(whitespace) or v.endswith(whitespace): + quote[i] = True + + def results(data): + for row in data: + result = [] + for i, v in enumerate(row): + quotation = quotestyle if quote[i] else '' + result.append('{quotestyle}{value}{quotestyle}'.format( + quotestyle=quotation, value=v)) + yield result + return results(data), headers + + +def style_output(data, headers, style=None, + header_token='Token.Output.Header', + odd_row_token='Token.Output.OddRow', + even_row_token='Token.Output.EvenRow', **_): + """Style the *data* and *headers* (e.g. bold, italic, and colors) + + .. NOTE:: + This requires the `Pygments <http://pygments.org/>`_ library to + be installed. You can install it with CLI Helpers as an extra:: + $ pip install cli_helpers[styles] + + Example usage:: + + from cli_helpers.tabular_output.preprocessors import style_output + from pygments.style import Style + from pygments.token import Token + + class YourStyle(Style): + default_style = "" + styles = { + Token.Output.Header: 'bold ansibrightred', + Token.Output.OddRow: 'bg:#eee #111', + Token.Output.EvenRow: '#0f0' + } + + headers = ('First Name', 'Last Name') + data = [['Fred', 'Roberts'], ['George', 'Smith']] + + data, headers = style_output(data, headers, style=YourStyle) + + :param iterable data: An :term:`iterable` (e.g. list) of rows. + :param iterable headers: The column headers. + :param str/pygments.style.Style style: A Pygments style. You can `create + your own styles <https://pygments.org/docs/styles#creating-own-styles>`_. + :param str header_token: The token type to be used for the headers. + :param str odd_row_token: The token type to be used for odd rows. + :param str even_row_token: The token type to be used for even rows. + :return: The styled data and headers. + :rtype: tuple + + """ + from cli_helpers.utils import filter_style_table + relevant_styles = filter_style_table(style, header_token, odd_row_token, even_row_token) + if style and HAS_PYGMENTS: + if relevant_styles.get(header_token): + headers = [utils.style_field(header_token, header, style) for header in headers] + if relevant_styles.get(odd_row_token) or relevant_styles.get(even_row_token): + data = ([utils.style_field(odd_row_token if i % 2 else even_row_token, f, style) + for f in r] for i, r in enumerate(data, 1)) + + return iter(data), headers + + +def format_numbers(data, headers, column_types=(), integer_format=None, + float_format=None, **_): + """Format numbers according to a format specification. + + This uses Python's format specification to format numbers of the following + types: :class:`int`, :class:`py2:long` (Python 2), :class:`float`, and + :class:`~decimal.Decimal`. See the :ref:`python:formatspec` for more + information about the format strings. + + .. NOTE:: + A column is only formatted if all of its values are the same type + (except for :data:`None`). + + :param iterable data: An :term:`iterable` (e.g. list) of rows. + :param iterable headers: The column headers. + :param iterable column_types: The columns' type objects (e.g. int or float). + :param str integer_format: The format string to use for integer columns. + :param str float_format: The format string to use for float columns. + :return: The processed data and headers. + :rtype: tuple + + """ + if (integer_format is None and float_format is None) or not column_types: + return iter(data), headers + + def _format_number(field, column_type): + if integer_format and column_type is int and type(field) in int_types: + return format(field, integer_format) + elif float_format and column_type is float and type(field) in float_types: + return format(field, float_format) + return field + + data = ([_format_number(v, column_types[i]) for i, v in enumerate(row)] for row in data) + return data, headers |