使用熊猫的 puthon 错误：TypeError: can only concatenate str (not "float") to str

Question

如何解决这个错误？

我正在做一些矩阵计算：

dataset=pd.read_csv('sample.csv')
 
dataset = dataset.to_numpy()
    
#Normalize the features using mean normalization
dataset = ( dataset - dataset.mean() ) / dataset.std()
    
dataset.head()       

我得到的错误是：

TypeError                                 Traceback (most recent call last)
   <ipython-input-122-74a855a3b4e2> in <module>
        28 
        29 #Normalize the features using mean normalization
   ---> 30 dataset = ( dataset - dataset.mean() ) / dataset.std()
        31 
        32 dataset.head()
        
   ~\anaconda3\lib\site-packages\numpy\core\_methods.py in _mean(a, axis, dtype, out, keepdims)
       158             is_float16_result = True
       159 
   --> 160     ret = umr_sum(arr, axis, dtype, out, keepdims)
       161     if isinstance(ret, mu.ndarray):
       162         ret = um.true_divide(
        
   TypeError: can only concatenate str (not "float") to str