searx.plugins.calculator Namespace Reference

Classes
class	SXNGPlugin

Functions
int	_compare (list[ast.cmpop] ops, list[int|float] values)
	_eval_expr (expr)
	_eval (node)
	handler (multiprocessing.Queue q, func, args, **kwargs)

Variables
dict	operators
dict	math_constants
	mp_fork = multiprocessing.get_context("fork")

Detailed Description

Calculate mathematical expressions using :py:obj:`ast.parse` (mode="eval").

Function Documentation

_compare()

int searx.plugins.calculator._compare ( list[ast.cmpop] ops, list[int | float] values )

protected

2 < 3 becomes ops=[ast.Lt] and values=[2,3]
2 < 3 <= 4 becomes ops=[ast.Lt, ast.LtE] and values=[2,3, 4]

Definition at line 120 of file calculator.py.

def _compare(ops: list[ast.cmpop], values: list[int | float]) -> int:
    """
    2 < 3 becomes ops=[ast.Lt] and values=[2,3]
    2 < 3 <= 4 becomes ops=[ast.Lt, ast.LtE] and values=[2,3, 4]
    """
    for op, a, b in zip(ops, values, values[1:]):  # pylint: disable=invalid-name
        if isinstance(op, ast.Eq) and a == b:
            continue
        if isinstance(op, ast.NotEq) and a != b:
            continue
        if isinstance(op, ast.Lt) and a < b:
            continue
        if isinstance(op, ast.LtE) and a <= b:
            continue
        if isinstance(op, ast.Gt) and a > b:
            continue
        if isinstance(op, ast.GtE) and a >= b:
            continue
 
        # Ignore impossible ops:
        # * ast.Is
        # * ast.IsNot
        # * ast.In
        # * ast.NotIn
 
        # the result is False for a and b and operation op
        return 0
    # the results for all the ops are True
    return 1
 
 

Referenced by _eval().

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_eval()

searx.plugins.calculator._eval ( node )

protected

Definition at line 209 of file calculator.py.

def _eval(node):
    if isinstance(node, ast.Constant) and isinstance(node.value, (int, float)):
        return node.value
 
    if isinstance(node, ast.BinOp):
        return operators[type(node.op)](_eval(node.left), _eval(node.right))
 
    if isinstance(node, ast.UnaryOp):
        return operators[type(node.op)](_eval(node.operand))
 
    if isinstance(node, ast.Compare):
        return _compare(node.ops, [_eval(node.left)] + [_eval(c) for c in node.comparators])
 
    if isinstance(node, ast.Name) and node.id in math_constants:
        return math_constants[node.id]
 
    raise TypeError(node)
 
 

References _compare(), and _eval().

Referenced by _eval(), and _eval_expr().

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_eval_expr()

searx.plugins.calculator._eval_expr ( expr )

protected

Evaluates the given textual expression.

Returns a tuple of (numericResult, isBooleanResult).

>>> _eval_expr('2^6')
64, False
>>> _eval_expr('2**6')
64, False
>>> _eval_expr('1 + 2*3**(4^5) / (6 + -7)')
-5.0, False
>>> _eval_expr('1 < 3')
1, True
>>> _eval_expr('5 < 3')
0, True
>>> _eval_expr('17 == 11+1+5 == 7+5+5')
1, True

Definition at line 181 of file calculator.py.

def _eval_expr(expr):
    """
    Evaluates the given textual expression.
 
    Returns a tuple of (numericResult, isBooleanResult).
 
    >>> _eval_expr('2^6')
    64, False
    >>> _eval_expr('2**6')
    64, False
    >>> _eval_expr('1 + 2*3**(4^5) / (6 + -7)')
    -5.0, False
    >>> _eval_expr('1 < 3')
    1, True
    >>> _eval_expr('5 < 3')
    0, True
    >>> _eval_expr('17 == 11+1+5 == 7+5+5')
    1, True
    """
    try:
        root_expr = ast.parse(expr, mode='eval').body
        return _eval(root_expr), isinstance(root_expr, ast.Compare)
 
    except (SyntaxError, TypeError, ZeroDivisionError):
        # Expression that can't be evaluated (i.e. not a math expression)
        return "", False
 
 

References _eval().

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handler()

searx.plugins.calculator.handler	(	multiprocessing.Queue	q,
			func,
			args,
		**	kwargs )

Definition at line 228 of file calculator.py.

def handler(q: multiprocessing.Queue, func, args, **kwargs):  # pylint:disable=invalid-name
    try:
        q.put(func(*args, **kwargs))
    except:
        q.put(None)
        raise

Variable Documentation

math_constants

dict searx.plugins.calculator.math_constants

Initial value:

=  {
    'e': math.e,
    'pi': math.pi,
}

Definition at line 168 of file calculator.py.

mp_fork

searx.plugins.calculator.mp_fork = multiprocessing.get_context("fork")

Definition at line 178 of file calculator.py.

operators

dict searx.plugins.calculator.operators

Initial value:

=  {
    ast.Add: operator.add,
    ast.Sub: operator.sub,
    ast.Mult: operator.mul,
    ast.Div: operator.truediv,
    ast.Pow: operator.pow,
    ast.BitXor: operator.xor,
    ast.BitOr: operator.or_,
    ast.BitAnd: operator.and_,
    ast.USub: operator.neg,
    ast.RShift: operator.rshift,
    ast.LShift: operator.lshift,
    ast.Mod: operator.mod,
    ast.Compare: _compare,
}

Definition at line 151 of file calculator.py.