I have 3 classes which are connected to them through inheritance as you see in
the below code:
import iso6346
class ShippingContainer:
"""docstring for ShippingContainer"""
HEIGHT_FT = 8.5
WIDTH_FT = 8.0
next_serial = 1337
@classmethod
def _get_next_serial(cls):
result = cls.next_serial
cls.next_serial += 1
return result
@staticmethod
def _make_bic_code(owner_code, serial):
return iso6346.create(owner_code=owner_code,
serial=str(serial).zfill(6))
@classmethod
def create_empty(cls, owner_code, length_ft, *args, **keyword_args):
return cls(owner_code, length_ft, contents=None, *args, **keyword_args)
# ... skipped
def __init__(self, owner_code, length_ft, contents):
self.contents = contents
self.length_ft = length_ft
self.bic = self._make_bic_code(owner_code=owner_code,
serial=ShippingContainer._get_next_serial())
# ... skipped
class RefrigeratedShippingContainer(ShippingContainer):
MAX_CELSIUS = 4.0
FRIDGE_VOLUME_FT3 = 100
def __init__(self, owner_code, length_ft, contents, celsius):
super().__init__(owner_code, length_ft, contents)
self.celsius = celsius
# ... skipped
@staticmethod
def _make_bic_code(owner_code, serial):
return iso6346.create(owner_code=owner_code,
serial=str(serial).zfill(6),
category='R')
@property
def celsius(self):
return self._celsius
@celsius.setter
def celsius(self, value):
if value > RefrigeratedShippingContainer.MAX_CELSIUS:
raise ValueError("Temperature too hot!")
self._celsius = value
# ... skipped
class HeatedRefrigeratedShippingContainer(RefrigeratedShippingContainer):
MIN_CELSIUS = -20.0
@RefrigeratedShippingContainer.celsius.setter
def celsius(self, value):
if value < HeatedRefrigeratedShippingContainer.MIN_CELSIUS:
raise ValueError("Temperature too cold!")
super().celsius = value
Now when I run the code :
Python 3.7.2 (v3.7.2:9a3ffc0492, Dec 24 2018, 02:44:43)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from shipping import * >>> h1 =
>>> HeatedRefrigeratedShippingContainer.create_empty('YML', length_ft=40,
>>> celsius=-18)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Users/aruprakshit/python_playground/shipping.py", line 23, in
create_empty
return cls(owner_code, length_ft, contents=None, *args, **keyword_args)
File "/Users/aruprakshit/python_playground/shipping.py", line 47, in __init__
self.celsius = celsius
File "/Users/aruprakshit/python_playground/shipping.py", line 92, in celsius
super().celsius = value
AttributeError: 'super' object has no attribute 'celsius'
>>>
Why here super is denying the fact that it has no celsius setter, although it
has. While this code doesn’t work how can I solve this. The thing I am trying
here not to duplicate the validation of temperature which is already in the
setter property of the RefrigeratedShippingContainer class.
Thanks,
Arup Rakshit
[email protected]
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