searx.plugins.calculator Namespace Reference

Functions
	_eval_expr (expr)
	_eval (node)
	handler (multiprocessing.Queue q, func, args, **kwargs)
	timeout_func (timeout, func, *args, **kwargs)
EngineResults	post_search (request, search)

Variables
str	name = "Basic Calculator"
	description = gettext("Calculate mathematical expressions via the search bar")
bool	default_on = True
str	preference_section = 'general'
str	plugin_id = 'calculator'
dict	operators
	mp_fork = multiprocessing.get_context("fork")

Detailed Description

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

Function Documentation

_eval()

searx.plugins.calculator._eval ( node )

protected

Definition at line 58 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))
 
    raise TypeError(node)
 
 

References _eval().

Referenced by _eval(), and _eval_expr().

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_eval_expr()

searx.plugins.calculator._eval_expr ( expr )

protected

>>> _eval_expr('2^6')
64
>>> _eval_expr('2**6')
64
>>> _eval_expr('1 + 2*3**(4^5) / (6 + -7)')
-5.0

Definition at line 42 of file calculator.py.

def _eval_expr(expr):
    """
    >>> _eval_expr('2^6')
    64
    >>> _eval_expr('2**6')
    64
    >>> _eval_expr('1 + 2*3**(4^5) / (6 + -7)')
    -5.0
    """
    try:
        return _eval(ast.parse(expr, mode='eval').body)
    except ZeroDivisionError:
        # This is undefined
        return ""
 
 

References _eval().

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handler()

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

Definition at line 71 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
 
 

post_search()

EngineResults searx.plugins.calculator.post_search	(		request,
			search )

Definition at line 97 of file calculator.py.

def post_search(request, search) -> EngineResults:
    results = EngineResults()
 
    # only show the result of the expression on the first page
    if search.search_query.pageno > 1:
        return results
 
    query = search.search_query.query
    # in order to avoid DoS attacks with long expressions, ignore long expressions
    if len(query) > 100:
        return results
 
    # replace commonly used math operators with their proper Python operator
    query = query.replace("x", "*").replace(":", "/")
 
    # use UI language
    ui_locale = babel.Locale.parse(request.preferences.get_value('locale'), sep='-')
 
    # parse the number system in a localized way
    def _decimal(match: re.Match) -> str:
        val = match.string[match.start() : match.end()]
        val = babel.numbers.parse_decimal(val, ui_locale, numbering_system="latn")
        return str(val)
 
    decimal = ui_locale.number_symbols["latn"]["decimal"]
    group = ui_locale.number_symbols["latn"]["group"]
    query = re.sub(f"[0-9]+[{decimal}|{group}][0-9]+[{decimal}|{group}]?[0-9]?", _decimal, query)
 
    # only numbers and math operators are accepted
    if any(str.isalpha(c) for c in query):
        return results
 
    # in python, powers are calculated via **
    query_py_formatted = query.replace("^", "**")
 
    # Prevent the runtime from being longer than 50 ms
    res = timeout_func(0.05, _eval_expr, query_py_formatted)
    if res is None or res == "":
        return results
 
    res = babel.numbers.format_decimal(res, locale=ui_locale)
    results.add(results.types.Answer(answer=f"{search.search_query.query} = {res}"))
 
    return results

References timeout_func().

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timeout_func()

searx.plugins.calculator.timeout_func	(		timeout,
			func,
		*	args,
		**	kwargs )

Definition at line 79 of file calculator.py.

def timeout_func(timeout, func, *args, **kwargs):
 
    que = mp_fork.Queue()
    p = mp_fork.Process(target=handler, args=(que, func, args), kwargs=kwargs)
    p.start()
    p.join(timeout=timeout)
    ret_val = None
    # pylint: disable=used-before-assignment,undefined-variable
    if not p.is_alive():
        ret_val = que.get()
    else:
        logger.debug("terminate function after timeout is exceeded")  # type: ignore
        p.terminate()
    p.join()
    p.close()
    return ret_val
 
 

Referenced by post_search().

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Variable Documentation

default_on

bool searx.plugins.calculator.default_on = True

Definition at line 21 of file calculator.py.

description

searx.plugins.calculator.description = gettext("Calculate mathematical expressions via the search bar")

Definition at line 20 of file calculator.py.

mp_fork

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

Definition at line 39 of file calculator.py.

name

str searx.plugins.calculator.name = "Basic Calculator"

Definition at line 19 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.USub: operator.neg,
}

Definition at line 25 of file calculator.py.

plugin_id

str searx.plugins.calculator.plugin_id = 'calculator'

Definition at line 23 of file calculator.py.

preference_section

str searx.plugins.calculator.preference_section = 'general'

Definition at line 22 of file calculator.py.