Re: [sage-support] Is it possible to add methods to an existing class at runtime ?

[Jori Mäntysalo]

On Sat, 8 Oct 2016, Emmanuel Charpentier wrote:

I wonder if it is possible to patch a new method in an existing class.

TypeError: can't set attributes of built-in/extension type 
'sage.symbolic.ex pression.Expression'

AFAIK it is impossible due to limitations of Python. You can patch classes 
not defined in C, like

type(Graph()).is_eulerian_and_hamiltonian = lambda self: self.is_eulerian() and 
self.is_hamiltonian()

but that won't work for example to Sage integers.

--
Jori Mäntysalo