Module whintpy.filters

Class BaseFilters

Description

Base class for any filter system.

Provides a foundational framework for filtering objects using various comparison methods. It ensures that the filtering criteria are valid and processes logical operations on these criteria.

Example

 >>> obj = SomeObject()
 >>> comparator = BaseComparator()
 >>> comparator._methods['exact'] = lambda x, y: x == y
 >>> kwargs = {'exact': "10"}
 >>> # Here it is:
 >>> base_filters = BaseFilters(obj)
 >>> BaseFilters.test_args(comparator, **kwargs)
 >>> logic_bool = BaseFilters.fix_logic_bool(**kwargs)
 >>> functions = BaseFilters.fix_functions(comparator, **kwargs)
 >>> # search for the object items matching the given filter
 >>> for item in obj:
 >>> if comparator.match(item, functions, logic_bool):
 >>> yield item

Constructor

Create a BaseFilters instance.

Parameters

obj: (object) Any type of object to be filtered.

View Source

def __init__(self, obj: object):
    """Create a BaseFilters instance.

    :param obj: (object) Any type of object to be filtered.

    """
    self._obj = obj

Public functions

test_args

Raise an exception if any of the kwargs is not correct.

Parameters

comparator: (BaseComparator)

Raises

KeyError: Invalid argument for the given comparator.

View Source

@staticmethod
def test_args(comparator: BaseComparator, **kwargs) -> None:
    """Raise an exception if any of the kwargs is not correct.

        :param comparator: (BaseComparator)
        :raises: KeyError: Invalid argument for the given comparator.

        """
    names = ['logic_bool'] + comparator.get_function_names()
    for func_name, value in kwargs.items():
        if func_name.startswith('not_'):
            func_name = func_name[4:]
        if func_name not in names:
            raise KeyError(f'Invalid kwargs function name {func_name}')

fix_logic_bool

Return the value of a logic boolean predicate.

Expect at least the "logic_bool" argument.

Raises

ValueError: Invalid logic bool value.

Returns

(str) "and" or "or". By default, the logical "and" is returned.

View Source

@staticmethod
def fix_logic_bool(**kwargs) -> str:
    """Return the value of a logic boolean predicate.

        Expect at least the "logic_bool" argument.

        :raises: ValueError: Invalid logic bool value.
        :return: (str) "and" or "or". By default, the logical "and" is returned.

        """
    for func_name, value in kwargs.items():
        if func_name == 'logic_bool':
            if value not in ['and', 'or']:
                raise ValueError('Invalid logic bool {}'.format(func_name))
            return value
    return 'and'

fix_functions

Parse the args to get the list of (function,value,complement).

The complement is a boolean which is True if the function is prefixed with "not_", meaning that the expected result is the opposite of the function.

Parameters

comparator: (BaseComparator)

Returns

(list) List of tuples with (function, value, complement)

View Source

@staticmethod
def fix_functions(comparator: BaseComparator, **kwargs) -> list:
    """Parse the args to get the list of (function,value,complement).

        The complement is a boolean which is True if the function is prefixed
        with "not_", meaning that the expected result is the opposite of the
        function.

        :param comparator: (BaseComparator)
        :return: (list) List of tuples with (function, value, complement)

        """
    f_functions = list()
    for func_name, value in kwargs.items():
        logical_not = False
        if func_name.startswith('not_'):
            logical_not = True
            func_name = func_name[4:]
        if func_name in comparator.get_function_names():
            f_functions.append((comparator.get(func_name), value, logical_not))
    return f_functions