python：AttributeError：'str'对象没有属性'keys'

如何解决python：AttributeError：'str'对象没有属性'keys'

我正在尝试解决分类问题。我不知道为什么会收到此错误：

AttributeError: 'str' object has no attribute 'keys'

这是主要代码：

def generate_arrays_for_training(indexPat,paths,start=0,end=100):       
    while True:
        from_=int(len(paths)/100*start)
        to_=int(len(paths)/100*end)
        for i in range(from_,int(to_)):
            f=paths[i]
            x = np.load(PathSpectogramFolder+f)
     if('P' in f):
                y = np.repeat([[0,1]],x.shape[0],axis=0)
            else:
                y =np.repeat([[1,0]],axis=0) 
            yield(x,y)
history=model.fit_generator(generate_arrays_for_training(indexPat,filesPath,end=75) ## problem here
                   steps_per_epoch=int((len(filesPath)-int(len(filesPath)/100*25))),validation_steps=int((len(filesPath)-int(len(filesPath)/100*75))),verbose=2,class_weight="balanced",epochs=15,max_queue_size=2,shuffle=True,callbacks=[callback])

其中generate_arrays_for_training函数返回x和y。 x是浮点数的2D数组，而y是[0,1]。

错误：

Traceback (most recent call last):
  File "/home/user1/thesis2/CNN_dwt2.py",line 437,in <module>
    main()
  File "/home/user1/thesis2/CNN_dwt2.py",line 316,in main
    history=model.fit_generator(generate_arrays_for_training(indexPat,end=75),File "/home/user1/.local/lib/python3.8/site-packages/tensorflow/python/util/deprecation.py",line 324,in new_func
    return func(*args,**kwargs)
  File "/home/user1/.local/lib/python3.8/site-packages/tensorflow/python/keras/engine/training.py",line 1815,in fit_generator
    return self.fit(
  File "/home/user1/.local/lib/python3.8/site-packages/tensorflow/python/keras/engine/training.py",line 108,in _method_wrapper
    return method(self,*args,line 1049,in fit
    data_handler = data_adapter.DataHandler(
  File "/home/user1/.local/lib/python3.8/site-packages/tensorflow/python/keras/engine/data_adapter.py",line 1122,in __init__
    dataset = dataset.map(_make_class_weight_map_fn(class_weight))
  File "/home/user1/.local/lib/python3.8/site-packages/tensorflow/python/keras/engine/data_adapter.py",line 1295,in _make_class_weight_map_fn
    class_ids = list(sorted(class_weight.keys()))

AttributeError: 'str' object has no attribute 'keys'

解决方法

您的问题是由您传递给class_weight="balanced"的{{1}}参数引起的

根据model.fit() reference，此参数应为dict：可选的字典映射类索引（整数）到权重（浮点）值，用于加权损失函数（仅在训练过程中）。这可能有助于告诉模型“更多关注”来自代表性不足的类的样本。

尝试model.fit()进行测试，它应该摆脱原始错误。稍后提供适当的字典作为class_weight=None，以解决数据集不平衡的问题。