CODEWITHSUNDEEP
pythonnameerror
raj89
raj89

Reputation: 1

Name Error: Global name 'r' is not defined

Ive been working on this sample code for a while and cant seem to wrap my head around this seemingly simple error.

The code is as follows:

class area :

    r=5
    l=2
    b=3

    def __init__(self,r,l,b):
        print "parent constructor"
        self.r=r
        self.l=l
        self.b=b

    def __del__(self):
        print "parent deconstructor"

    def circle(self):

        circle_area= 3.14 * r * r
        print "area of circle is :",circle_area 

    def rectangle(self):
        rect_area=l*b
        print "area of rectangle :",rect_area

obj=area(4,5,4)
obj2=area(2,5,4)

obj.circle()

The error message says : 

File "yaa.py", line 18, in circle
    circle_area= 3.14 * r * r
NameError: global name 'r' is not defined.

Upvotes: 0

Views: 9307

Answers (2)

Netwave
Netwave

Reputation: 42716

You need to use the self for refering class attributes:

def circle(self):
    circle_area= 3.14 * self.r * self.r
    print "area of circle is :",circle_area

In case you want to use the r within the class, not the instance you have to use the name of the class then:

def circle(self):
    circle_area= 3.14 * area.r * area.r
    print "area of circle is :",circle_area

Upvotes: 3

Ralf
Ralf

Reputation: 16505

You probably need to change your method circle(self) from

circle_area= 3.14 * r * r

to 

circle_area= 3.14 * self.r * self.r

because r is an attribute of the class, not a global variable.

The same goes for your method rectangle(self):

rect_area = self.l * self.b

Upvotes: 1

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