I should clarify that what I said is opinionated (my opinion in
particular!) so it's possible others disagree. Certainly there is a
lot of code in SymPy that doesn't follow the advice above.
If we want a cached_property decorator then we can add this somewhere
in sympy/utilities or perhaps
Great, that is exactly what I've been trying to find!
By the way, there is caching property decorator called `@cached_property`,
that does exactly what you suggested. It is, however, not in the standard
library (https://pypi.org/project/cached-property/). Maybe it would be
beneficial to add it to
Preventing assignment isn't necessary for the internal workings of
SymPy. The only advantage it has is potentially avoiding confusion for
users. I don't particularly see users getting confused about this
though (although maybe that's because of the widespread use of
properties).
What I think is
There are several ways to implement properties of sympy objects. The
simplest one is:
```
def __new__(*args):
obj = Basic(*args)
obj.prop = 'some_property'
```
A slightly more complicated one is:
```
def __new__(*args):
obj = Basic(*args)
obj._prop = 'some_property'
@property
def
