# Revision history [back]

If you type

sage: f??


You will see that the method .__call__ (responsible for the behaviour of evaluating f) is the one-liner

return vector([e(*args, **kwargs) for e in self])


This has been designed so that symbolic functions can safely be used in symbolic expressions in a meaningful way.

There is no way around it. If you really only need to return a list, then an ordinary python function (like (2) or (3)) is probably enough. Or you can convert the output of f to a list like so:

sage: list(f(x))


If you type

sage: f??


You will see that the method .__call__ (responsible for the behaviour of evaluating f) is the one-liner

return vector([e(*args, **kwargs) for e in self])


This has been designed so that symbolic functions can safely be used in symbolic expressions in a meaningful way.way. For example, you can combine f with another symbolic function using the vector product operator *:

sage: f(x) = [x,x]
sage: f
x |--> (x, x)
sage: f * f
x |--> 2*x^2


This would not work with ordinary python lists.

There is no way around it. If you really only need to return a list, then an ordinary python function (like (2) or (3)) is probably enough. Or you can convert the output of f to a list like so:

sage: list(f(x))