如何为类对象中的"dtype"参数引发错误

Question

我有以下代码：

import numpy as np
class circle(object):
def __init__(self, radius=3, color='blue', data_type=np.float64):   # default values
self.radius = radius
self.color = color 
self.data_type = data_type

if self.data_type not in [np.float32, np.float64]:
raise ValueError('data_type should be np.float32 or np.float64 only')

def add_radius(self, r):
self.radius = self.radius + np.ceil(r, dtype=self.data_type)
return(self.radius)

redcircle = circle(radius=10, color='red', data_type=np.float32)
redcircle.add_radius(2.323) 

当我运行代码时，我得到以下错误：

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-39-27704fa7e57b> in <module>
----> 1 class circle(object):
2     def __init__(self, radius=3, color='blue', data_type=np.float64):   # default values
3         self.radius = radius
4         self.color = color
5         self.data_type = data_type
<ipython-input-39-27704fa7e57b> in circle()
5         self.data_type = data_type
6 
----> 7     if self.data_type not in [np.float32, np.float64]:
8         raise ValueError('dtype should be np.float32 or np.float64 only')
9 
NameError: name 'self' is not defined

如何在类对象中指定dtype参数，以便在指定的dtype参数值不是类对象可接受的值时引发错误？

如果有人知道的话，非常感谢。

Answer 1

Python的结构完全由缩进级别控制：

class circle(object):
def __init__(self, radius=3, color='blue', data_type=np.float64):   # default values
self.radius = radius
self.color = color 
self.data_type = data_type
# Python assumes this is the end of the __init__ function
# because this next line is at the next higher level
if self.data_type not in [np.float32, np.float64]:
raise ValueError('data_type should be np.float32 or np.float64 only')

# so the above is a fragment that will not run in __init__. 
def add_radius(self, r):
self.radius = self.radius + np.ceil(r, dtype=self.data_type)
return(self.radius)

这能回答你的问题吗？