Python find method in class -

i have defined class called point defines point in x, y coordinate system. definition , methods shown below. created own version of str method return created point in printable form (required). however, when try pass returned point method determine distance between 2 points (p1 , p2), using call p.distanceto(p2), following error attempt parse string (p2) passed method:

attributeerror: point instance has no attribute 'find' 

when pass in string defined p2 should works fine. appreciated. thank you.

here code:

class point:     """ define point     """     def __init__(self, x=0, y=0):         self.x = x         self.y = y      def __str__(self):         return "(" + str(self.x) + "," + str(self.y) + ")"      def __getitem__(self,i):         return      def __find__(self,j):         return j      def distanceto(self,p2):         idx1 = p2.find("(")         idx2 = p2.find(",")         idx3 = p2.find(")")          x2 = int(p2[idx1+1:idx2])         y2 = int(p2[idx2+1:idx3])          dist = math.sqrt(math.pow((x2-self.x),2)+math.pow((y2-self.y),2))         return  dist   p1=point()  p2=point(3,4)  print p1.distanceto(p2) 

you named method __find__. remove double underscores:

def find(self, j):     return j 

you should use __...__ "dunder" (double underscore) method names special method names avoid confusion , future name clashes.

however, passing in point instance, access attributes directly:

def distanceto(self,p2):     x2 = p2.x     y2 = p2.y      dist = math.sqrt(math.pow((x2-self.x),2)+math.pow((y2-self.y),2))     return  dist 

or, further simplified, using underscore_name style used in python methods:

def distance_to(self, p2):     return math.sqrt(math.pow((p2.x - self.x), 2) + math.pow((p2.y - self.y), 2)) 

you can remove __find__ , __getitem__ methods, attempts @ making .distanceto() method work.

the full class becomes:

class point(object):     """define point"""      def __init__(self, x=0, y=0):         self.x = x         self.y = y      def __str__(self):         return "({0.x}, {0.y})".format(self)      def distance_to(self, p2):         return math.sqrt(math.pow((p2.x - self.x), 2) + math.pow((p2.y - self.y), 2)) 

using little more python idiom class (inheriting object) , __str__ method (using string formatting).

now class behaves expected:

>>> p1 = point() >>> p2 = point(3,4) >>> print p1 (0, 0) >>> print p2 (3, 4) >>> print p1.distance_to(p2) 5.0 

class instances not strings, , although can converted strings (when printed example), don't need treat them strings. access attributes directly.