Python：在字典裏面加上元組的產品

Question

我有一個帶有鍵控元組的字典。我想爲每個字典鍵乘以2個元組和總和。

我創建了兩個類。第一個（ExampleBase）只是創建一個變量和一個字典。第二個（Useful）傳遞字典並進行計算。

我相信我打電話從第二類（Useful）的方法不正確地作爲目前我得到的錯誤是：「ExampleBase」 objest有沒有屬性「compute_value」

的代碼應該這樣做：

dictionary = { 
    "key1": (v1, v2), 
    "key2": (v1, v2), 
    "key3": (v1, v2) 
} 

total = key1v1*key1v2 + key2v1*key2v2 + key3v1*key3v2 

---

class ExampleBase: 
    def __init__(self, company_name="N/A", stock_dict={}): 
     """ 
     class constructor 
     """ 
     self.company_name = company_name 
     self.stock_dict = stock_dict 
     print(self.stock_dict)  
     return 


class Useful(ExampleBase): 
    """ 
    Inherits from ExampleBase class 
    """ 
    def __init__(self, company_name, stock_dict): 
     super().__init__(name) 
     return 


    def compute_value(self, stock_dict): 
     """ 
     Computes value of stk 
     """ 
     sum(v1*v2 for v1,v2 in stock_dict.values()) 
     return 

## 
## Program starts running from here 
## 
if __name__ == "__main__": 
    a = {"10-01-2014":(10, 11.25), "10-02-2014":(11, 12.25), "10-03-2014":(12, 13.25)} 
    b = ExampleBase("Bern", a) 
    b.compute_value(a) 

Answer 1

我覺得你compute_value功能幾乎沒有。我完成你的代碼。關於這個錯誤，那是因爲你從ExampleBase調用函數。

class ExampleBase: 
    def __init__(self, company_name="N/A", stock_dict={}): 
     """ 
     class constructor 
     """ 
     self.company_name = company_name 
     self.stock_dict = stock_dict 
     print(self.stock_dict)  
     return 


class Useful(ExampleBase): 
    """ 
    Inherits from ExampleBase class 
    """ 
     def __init__(self, company_name, stock_dict): 
      super().__init__(company_name) 
      return 


     def compute_value(self, stock_dict): 
      """ 
      Computes value of stk 
      """ 
      val = sum(v1*v2 for v1,v2 in stock_dict.values()) 
      return val 

    ## 
    ## Program starts running from here 
    ## 
    if __name__ == "__main__": 
     a = {"10-01-2014":(10, 11.25), "10-02-2014":(11, 12.25), "10-03-2014":(12, 13.25)} 
     b = Useful("Bern", a) 
     value = b.compute_value(a) 
     print(value) 

另外，如果您打算爲compute_value是計算stock_dict當你創建Useful實例給出 類更是這樣的：

class Useful(ExampleBase): 
    """ 
    Inherits from ExampleBase class 
    """ 
    def __init__(self, company_name, stock_dict): 
     super().__init__(company_name, stock_dict) 
     return 


    def compute_value(self): 
     """ 
     Computes value of stk 
     """ 
     val = sum(v1*v2 for v1,v2 in self.stock_dict.values()) 
     return val 

與main：

if __name__ == "__main__": 
    a = {"10-01-2014":(10, 11.25), "10-02-2014":(11, 12.25), "10-03-2014":(12, 13.25)} 
    b = Useful("Bern", a) 
    value = b.compute_value() 
    print(value) 

Answer 2

這是你在找什麼？

如果你知道每個鍵都將有長度爲2的元組值：

d = {'a': (1, 2), 'b': (3, 4)} 
total = sum(a * b for a, b in d.values()) 
# total => 10 

否則：

import operator 
from functools import reduce 
d = {'a': (1, 2), 'b': (3, 4, 5)} 
total = sum(reduce(operator.mul, a, 1) for a in d.values()) 
# total => 62