comparing int float python problem

I have this code:

def fit(self,p1,p2,w):
    p=p1    
    m=self.bit(p,w)
    if p1.y!=p2.y:
        if m&0x30:
            p.y=w.y1 if m&0x10 else w.y2-1
            try:
                p.x=int((p.y-p2.y)*(p1.x-p2.x)/(p1.y-p2.y)+p2.x)
            except Exception,e:
                print e
                print p1.y!=p2.y        
                print p1.y,p2.y

The output is:

cannot convert float NaN to integer开发者_运维技巧  
False  
199 199.0

I have no idea why p1.y!=p2.y evaluates to true and then in the exception it evaluates to false

I'm running python 2.6.6

---

You are dividing 0/0!

# (p.y-p2.y)*(p1.x-p2.x)
x = p.y - p2.y
x = 199 - 199.0 = 0
x1 = p1.x-p2.x
0 * x1 = 0* p1.x - 0* p2.x

This means

(p.y-p2.y)*(p1.x-p2.x) = 0

Now we are devising 0 by this:

#(p1.y-p2.y)
p1.y-p2.y
x = p.y - p2.y
x = 199 - 199.0 = 0

So in this case you are trying to do 0/0

Then at the end of the whole thing you try to add p2.x and i believe thats why you get the error cannot convert float NaN to integer and not ZeroDivisionError: integer division or modulo by zero

Its really easy to solve. change if p1.y!=p2.y: line 4 to If p1.y-p2.y != 0: