Garret Ulrich - 8 months ago 38

Python Question

I was wondering how I can calculate the perimeter of my object called 'Rectangle' if I do not have the x-coordinates and y-coordinates saved in the Rectangle class.

`class Point:`

def __init__(self, xcoord=0, ycoord=0):

self.x = xcoord

self.y = ycoord

def setx(self, xcoord):

self.x = xcoord

def sety(self, ycoord):

self.y = ycoord

def get(self):

return (self.x, self.y)

def move(self, dx, dy):

self.x += dx

self.y += dy

class Rectangle:

def __init__(self, bottom_left, top_right, colour):

self.bottom_left = bottom_left

self.top_right = top_right

self.colour = colour

def get_colour(self):

return self.colour

def get_bottom_left(self):

return self.bottom_left

def get_top_right(self):

return self.top_right

def reset_colour(self, colour):

self.colour = colour

def move(self,dx,dy):

Point.move(self.bottom_left,dx,dy)

Point.move(self.top_right,dx,dy)

def get_perimeter(self):

I am calling the function in python shell in the following format

`r1=Rectangle(Point(),Point(1,1),'red')`

r1.get_perimeter()

Answer Source

That's more basic geometry than Python.

Since you only provide bottom left and top right points I'm assuming that the rectangle has sides parallel to x/y axis. In that case:

```
def get_perimeter(self):
return 2*(abs(self.top_right.x-self.bottom_left.x)+abs(self.bottom_left.y-self.top_right.y))
```

I've put the `abs`

function for good measure because left & right, top & bottom doesn't presuppose of the orientation of the coordinate system.

Note: you *have* `x`

and `y`

of the 2 defining points "saved" (accessible) in your `Rectangle`

class, not directly as a direct member, but as a member of a member.