三元运算符 np.where，裁剪clip

 1 import numpy as np
 2 def fill_ndarray(t1):
 3     for i in range(t1.shape[1]):   #一列一列的循环
 4         temp_col = t1[:,i]
 5         nan_num = np.count_nonzero(temp_col!=temp_col)
 6         if nan_num !=0:  #不为0 说明当前这一列有nan
 7             tem_not_nan_col = temp_col[temp_col==temp_col] #当前一列不为nan的array
 8             #选中当前nan的位置，替换为当前列不为nan的值的均值
 9             temp_col[np.isnan(temp_col)] = tem_not_nan_col.mean()
10     return t1
11 
12 if __name__ == ‘__main__‘:
13     t1 = np.arange(12).reshape(3,4).astype(‘float‘)
14     t1[1,2:] = np.nan
15     t2 = fill_ndarray(t1)
16     print(t2)