[Python知识库]python篇---如何传递运算表达式

#-- coding: utf-8 --
import operator


class Expression:
    def __eq__(self, other):
        return Operator("==", other)
    def __lt__(self, other):
        return Operator("<", other)
    def __le__(self, other):
        return Operator("<=", other)
    def __gt__(self, other):
        return Operator(">", other)
    def __ge__(self, other):
        return Operator(">=", other)


class Operator:
    def __init__(self, operator_, rhs):
        self._operator = operator_
        self._rhs = rhs
        self._operator_map = {
            "==": operator.eq,
            "<": operator.lt,
            "<=": operator.le,
            ">": operator.gt,
            ">=": operator.ge
        }

    @property
    def value(self):
        return self._rhs

    @property
    def operator(self):
        return self._operator_map[self._operator]


def pick_range(data, left_exp, right_exp):
    lvalue = left_exp.value
    rvalue = right_exp.value
    loperator = left_exp.operator
    roperator = right_exp.operator
    return [item for item in data if loperator(item, lvalue) and roperator(item, rvalue)]


exp = Expression()
data = [1, 2, 3, 4, 5, 6, 7]
print(pick_range(data, 1 < exp, exp < 6))


def pick_range1(data, exp):
    value = exp.value
    operator = exp.operator
    return [item for item in data if operator(item, value)]

exp = Expression()
data = [1, 2, 3, 4, 5, 6, 7]
print(pick_range1(data, 1 < exp))