add parentheses to method area_code

[YuriyCherniy]

Without parentheses the test_area_code is trying compare this: <bound method Phone.area_code of <phone_number.Phone object at 0x7f0426e266d8>> != '223' instead of this: '223' == '223' so the test cannot be passed.

[cmccandless]

This is not a bug. Phone.area_code should be a property, not a method.

[YuriyCherniy]

This is not a bug. Phone.area_code should be a property, not a method.

But why without parentheses test returns FAILED (failures=1)? and with parentheses OK?

[cmccandless]

Because you've implemented Phone.area_code as a method in your solution. This is incorrect. Correct example:

class Phone(object):
    def __init__(self, number):
        self.area_code = <value of area code>

[YuriyCherniy]

Because you've implemented Phone.area_code as a method in your solution. This is incorrect. Correct example:

class Phone(object):
    def __init__(self, number):
        self.area_code = <value of area code>

Ok. I got it. Thank you.