「列表」對象沒有屬性「方法」

Question

我與測量值的列表，如：

[[Measurements(100, 0.3)], 
[Measurements(33, 0.5)]] 

然後，我有一些標準的列表，其包含的測量列表：

[Criteria(999, [[Measurements(100, 0.3)], 
         [Measurements(33, 0.5)]])], 

[Criteria(999, [[Measurements(150, 0.3)], 
         [Measurements(35, 0.5)]])] 

最後，我想提供上述列表作爲輸入並執行代碼：

class Measurements(): 
    def __init__(self, value, other): 
     self.value = value 
     self.other = other 


class Criteria(): 
    def __init__(self, new_value, measurements): 
     self.new_value = new_value 
     self.measurements = measurements 

    def method(self): 

     # Here, I am iterating through all measurements 
     # and replace the value according to criteria 
     for idx, x in enumerate(self.measurements): 
      if (self.measurements[idx].value > 20 and 
        self.measurements[idx].value < 110): 

       self.measurements[idx].value = self.new_value 
     return self.measurements 


class Evaluate(): 
    def __init__(self, criteria): 
     self.criteria = criteria 

    def execute(self): 
     criteria = self.criteria 

     # Here, I am iterating through all criteria 
     # and call the method from criteria 
     for i, c in enumerate(criteria): 
      c.method() 
      return c.measurements 


def main(): 

    criteria = [ 
     [Criteria(999, [[Measurements(100, 0.3)], 
         [Measurements(33, 0.5)]])], 

     [Criteria(999, [[Measurements(150, 0.3)], 
         [Measurements(35, 0.5)]])] 
    ] 

    obs = (Evaluate(criteria).execute()) 


if __name__ == "__main__": 
    main() 

和我收到c.method() AttributeError: 'list' object has no attribute 'method'

我想我的結果是新的校正測量，所以：

[[Measurements(999, 0.3)], 
[Measurements(999, 0.5)]], 
[Measurements(150, 0.3)], 
[Measurements(999, 0.5)]] 

Answer 1

你所有的Criteria()和Measurement()對象中的每個存儲在一個元素的列表，而這又是存儲在一個較大名單。要麼爲此考慮，要麼不使用單元素嵌套列表。

我沒有看到這些單元素列表的任何理由;下面的定義應該讓你的代碼工作：

criteria = [ 
    Criteria(999, [Measurements(100, 0.3), Measurements(33, 0.5)]), 
    Criteria(999, [Measurements(150, 0.3), Measurements(35, 0.5)]), 
] 

你反之則要要麼提取每一次，或使用嵌套循環一個元素：

def execute(self): 
    for c in self.criteria: 
     c[0].method() 

或

def execute(self): 
    for c_list in self.criteria: 
     for c in c_list: 
      c.method() 

您還應該而不是在for循環中使用return，至少在您想要測量全部標準。將測量值收集到列表中，然後返回該列表。

您還在Criteria.method()循環中使用self太多次。不需要enumerate()，您不需要索引來更改可變對象。

更正代碼：

class Measurements(): 
    def __init__(self, value, other): 
     self.value = value 
     self.other = other 


class Criteria(): 
    def __init__(self, new_value, measurements): 
     self.new_value = new_value 
     self.measurements = measurements 

    def method(self): 
     for measurement in self.measurements: 
      if 20 < measurement.value < 110: 
       measurement.value = self.new_value 
     return self.measurements 

class Evaluate(): 
    def __init__(self, criteria): 
     self.criteria = criteria 

    def execute(self): 
     results = [] 
     for c in self.criteria: 
      measurements = c.method() 
      results.extend(measurements) 
     return results 

def main(): 
    criteria = [ 
     Criteria(999, [Measurements(100, 0.3), Measurements(33, 0.5)]), 
     Criteria(999, [Measurements(150, 0.3), Measurements(35, 0.5)]), 
    ] 

    obs = Evaluate(criteria).execute()