在与它一起玩.之后,我更想一遍。 当我第一次问问过我所知道的。
因此,本on会议将做些什么?
>>> from sympy import *
>>> x = Symbol(x)
>>> x + x
2*x
它只字不提解释者如何评价这一表述;重要的是,假装翻译。
页: 1
<代码>x.__add__(x)
www.un.org/spanish/ga/president (如果你想看一看的话,这些班级见有症状,有分,有症状。
So as Jerub was saying, Symbol.__add__() has a decorator called _sympifyit which basically converts the second argument of a function 页: 1 a sympy expression before evaluating the function, in the process returning a function called __sympifyit_wrapper which is what I saw before.
利用目标来界定行动是一个极好的浮雕概念;通过界定你自己的运营商和代表,你可以非常容易地实施一种三维象征的algebra系统:
象征意义——
class Symbol(object):
def __init__(self, name):
self.name = name
def __add__(self, other):
return Add(self, other)
def __repr__(self):
return self.name
class Add(object):
def __init__(self, left, right):
self.left = left
self.right = right
def __repr__(self):
return self.left + + + self.right
我们现在可以做到:
>>> from symbolic import *
>>> x = Symbol( x )
>>> x+x
x+x
参照/数据模型.html
class Basic(object):
def __add__(self, other):
return Add(self, other)
def __radd__(self, other): # if other hasn t implemented __add__() for Symbols
return Add(other, self)
def __mul__(self, other):
return Mul(self, other)
def __rmul__(self, other):
return Mul(other, self)
# ...
class Symbol(Basic):
def __init__(self, name):
self.name = name
def __repr__(self):
return self.name
class Operator(Basic):
def __init__(self, symbol, left, right):
self.symbol = symbol
self.left = left
self.right = right
def __repr__(self):
return {0}{1}{2} .format(self.left, self.symbol, self.right)
class Add(Operator):
def __init__(self, left, right):
self.left = left
self.right = right
Operator.__init__(self, + , left, right)
class Mul(Operator):
def __init__(self, left, right):
self.left = left
self.right = right
Operator.__init__(self, * , left, right)
# ...
仅仅稍微加大 t缩,我们从一开始便能够采取与感冒会议相同的行动。 因此,如果其论点相同,它可退回<代码>Mul。 这是一种比喻的trick,因为我们已经到了<>>>>>>>>>之前,不得不使用,而不是<>>>>>>><>>><>>>>>>>>>:
class Add(Operator):
def __new__(cls, left, right):
if left == right:
return Mul(2, left)
return Operator.__new__(cls)
...
Don forget implement :
class Symbol(Basic):
...
def __eq__(self, other):
if type(self) == type(other):
return repr(self) == repr(other)
else:
return False
...
And voila。 无论怎样,你们都可以想到其他各种东西来执行,如经营者的头等,以替代方式进行评价、先进的简化、区别等等,但我认为,基本内容非常简单。
