Re: [Visualpython-users] Re: strange output

I feared in the back of my mind, my answer posted this morning is dead
wrong.  My answer had assumed
that ball.pos could be treated as a normal Python list Which is not the
case. It is of type "vector", which is not a native Python type, but one
coming over from the cvisual code.  As such it turns out it is neither
sliceable or copyable.

The *right* answer here seems to be:

rinitial=list(ball.pos)
or
rinitial=tuple(ball.pos)

This stores rinital in a separate object not effected by changes in
ball.pos, but which can work for
ball.pos=rinital
should one want to restore the initial position of ball.

I think.

Sorry for the misinfo.

Art



>I think it worth supplementing Bruce's analysis with the solution to what
was trying to be accomplished by

>rininitial = ball.pos

>I believe either:

>rinitial = ball.pos[:]

>or

>rinitial =copy(ball.pos)

>would get one to where one is trying to go.

>[:] returns a complete "slice" of the list.
>copy, of course, a copy of the list.

>In either case rinitial is no longer an additional name for ball.pos, but
an
>object independant of it, which will not be modified upon the modification
>of ball.pos.

>I think I have this right.  Corrections welcome.

>Art