Okay. So, this is what happens if I use __init__:
Symbol.__new__ is called. Here's the definition:
def __new__(cls, name, **assumptions):
"""Symbols are identified by name and assumptions::
As you can see, the method expects 2 positional arguments and rest are
keyword arguments (the assumptions). When I use __init__, the function call
is something like this:
def __init__(self, name, coord_sys, position, **assumptions):
And that's the error.
Now, even if I can use __init__, here's what will happen:
Symbol.__new__ still gets called first. Inside Symbol.__new__, it makes
this call:
return Symbol.__xnew_cached_(cls, name, **assumptions)
The method __xnew_cached is cached. So, if the symbol with the same name
had already been defined, that gets returned instead of a new object.
Therefore, we are back to our original problem - that symbol doesn't
support any extra args. In fact, if we have a symbol, doing:
>>> symbol.args
returns an empty tuple.
--
You received this message because you are subscribed to the Google Groups
"sympy" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to sympy+unsubscr...@googlegroups.com.
To post to this group, send email to sympy@googlegroups.com.
Visit this group at http://groups.google.com/group/sympy.
For more options, visit https://groups.google.com/groups/opt_out.
