[Tutor] How to extract a float from an instancemethod call

[Yaniv Bronheim]

by reading the exception you see that you pass function pointer instead of a value
"KeyError: (<bound method Position.getX of <__main__.Position object at 
0x4699490>>, <bound method Position.getY of <__main__.Position object at 
0x4699490>>)"

as if you just print pos.getX and not pos.getX(), you will see the exact output - <__main__.Position object at 0x4699490>
..

Regards,
Yaniv.

----- Original Message -----
> From: "Sydney Shall" <s.shall at virginmedia.com>
> To: "Dave Angel" <davea at davea.name>
> Sent: Monday, April 8, 2013 5:49:50 PM
> Subject: Re: [Tutor] How to extract a float from an instancemethod call
> 
> 
> 
> On 08/04/2013 13:52, Dave Angel wrote:
> > On 04/08/2013 08:40 AM, Sydney Shall wrote:
> >> Hi,
> >> I am  learning Python.
> >>
> >> I use MAC OSX 10.6.8
> >> Python 2.7.3
> >>
> >> I have been given a project to write a program involving random walks.
> >> I have drafted a program which has passed all the static tests, but on
> >> testing my program i get the following error message:
> >>
> >>
> >> Traceback (most recent call last):
> >>    File "/Users/Sydney/Documents/6.00x Files/Problem
> >> Sets/ProblemSet7/ps7 copy.py", line 303, in <module>
> >>      testRobotMovement(StandardRobot, RectangularRoom)
> >>    File "ps7_verify_movement.py", line 12, in testRobotMovement
> >>    File "/Users/Sydney/Documents/6.00x Files/Problem
> >> Sets/ProblemSet7/ps7 copy.py", line 285, in updatePositionAndClean
> >>      while self.room.isPositionInRoom(self.position) == False:
> >>    File "/Users/Sydney/Documents/6.00x Files/Problem
> >> Sets/ProblemSet7/ps7 copy.py", line 163, in isPositionInRoom
> >>      return self.room[(x,y)] in self.room
> >> KeyError: (<bound method Position.getX of <__main__.Position object at
> >> 0x4699490>>, <bound method Position.getY of <__main__.Position object at
> >> 0x4699490>>)
> >>  >>>
> >>
> >> The program text referred to is the following, I give the whole module,
> >> which is part of a larger program.
> >>   def isPositionInRoom(self, pos):
> >>          """
> >>          Return True if pos is inside the room.
> >>
> >>          pos: a Position object.
> >>          returns: True if pos is in the room, False otherwise.
> >>          """
> >>          x = pos.getX
> >>          y = pos.getY
> >
> > You never show the code for Position.getX and Position.getY, but I'd
> > expect they're methods that take no arguments.  in that case, you need
> > parens in order to call them.
> >
> >            x = pos.getX()
> >            y = pos.getY()
> >
> >>          return self.room[(x,y)] in self.room
> >>
> >
> > a simple print of x and y could have revealed this as well.
> >
> >
> Dear Dave,
> Thanks for  pointing out my mistake. I thought it would be some small
> error on my part.
> I had a print statement, but I could not correctly interpret the output.
> It solves that problem.
> 
> 
> 
> --
> Sydney Shall
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