類特殊方法行爲__complex__

Question

我有一個類定義了__complex__特殊方法。我的階級是不是一個標準的數字類型（整型，浮點等），但它的行爲就像一個我已經爲__add__，__sub__定義的特殊方法等

我想__complex__回到我的復值的數字對象，而不是python期望的標準複雜數值。因此，當我嘗試返回我的對象​​時，Python會拋出以下錯誤，而不是標準的複數數字。

TypeError: unsupported operand type(s) for *: 'complex' and 'MyNumericClass'

這樣做的最好方法是什麼？

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編輯：

# Python builtins 
import copy 
# Numeric python 
import numpy as np 

class MyNumericClass (object): 
    """ My numeric class, with one single attribute """ 
    def __init__(self, value): 
     self._value = value 

    def __complex__(self): 
     """ Return complex value """ 
     # This looks silly, but my actual class has many attributes other 
     # than this one value. 
     self._value = complex(self._value) 
     return self 

def zeros(shape): 
    """ 
    Create an array of zeros of my numeric class 

    Keyword arguments: 
     shape -- Shape of desired array 
    """ 
    try: 
     iter(shape) 
    except TypeError, te: 
     shape = [shape] 
    zero = MyNumericClass(0.) 
    return fill(shape, zero) 

def fill(shape, value): 
    """ 
    Fill an array of specified type with a constant value 

    Keyword arguments: 
     shape -- Shape of desired array 
     value -- Object to initialize the array with 
    """ 
    try: 
     iter(shape) 
    except TypeError, te: 
     shape = [shape] 
    result = value 
    for i in reversed(shape): 
     result = [copy.deepcopy(result) for j in range(i)] 
    return np.array(result) 

if __name__ == '__main__': 
    a_cplx = np.zeros(3).astype(complex) 
    print a_cplx 
    b_cplx = zeros(3).astype(complex) 
    print b_cplx 

Answer 1

幾個選項：

1. 定義__rmul__（或定義__mul__和翻轉乘法操作數）。
2. 在乘以之前將MyNumericClass實例投射到complex。