threaded_cached_property can raise confusing exception #260
Description
When the function decorated by threaded_cached_property raises an exception, rather than the exception from the user code being front-and-center, users are presented first with the cached property KeyError, only to see their real error further down the line.
Take for example the following code and resulting traceback.
class Monopoly(object):
def __init__(self):
self.boardwalk_price = 500
@threaded_cached_property
def boardwalk(self):
self.boardwalk_price += 1/0
return self.boardwalk_price
m = Monopoly()
m.boardwalkTraceback (most recent call last):
File "/Users/spencer.young/repos/cached-property/cached_property.py", line 70, in __get__
return obj_dict[name]
KeyError: 'boardwalk'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "t.py", line 15, in <module>
m.boardwalk
File "/Users/spencer.young/repos/cached-property/cached_property.py", line 74, in __get__
return obj_dict.setdefault(name, self.func(obj))
File "t.py", line 11, in boardwalk
self.boardwalk_price += 1/0
ZeroDivisionError: division by zeroThe traceback presents first, a KeyError which could be confusing to the user. Instead, it would be nice if cached-property would avoid this in such a way that only the relevant ZeroDivisionError would surface.