error in class: TypeError: 'str' object is not callable

[akbarza]

in below code:

class Person:
     def __init__(self,username):
         self._username= username

     #getter
     @property
     def username(self):
         return  self._username

     #setter
     @username.setter
     def username(self,name):
         if not isinstance(name, str):
             raise TypeError('expected a string object.')
         self._username=name.lower()

p=Person('ali')
print(f"p.username is :{p.username}")
p.username('mohammad')
print(f" after p.username('mohammad'), p.username results: {p.username}")

after run, the below error appeared:

Error:
Traceback (most recent call last):
  File "<pyshell#14>", line 1, in <module>
    p.username("mohammad")
TypeError: 'str' object is not callable

what is the problem?
thanks

[Gribouillis]

what is the problem?

The problem is that p.username is the string 'ali'. So if you write p.username('mohammad'), it is as if you write 'ali'('mohammad') which is a type error. The correct syntax is p.username = 'mohammad'.

[deanhystad]

The problem is Person.username is a property. Properties are referenced like attributes, even though they look like a method in your code. The correct way to set a property is use assignment.

p.username = 'mohammad'

I would call this a bug:

     def __init__(self,username):
         self._username= username

According to the username setter, usernames have to be lower case, but your code allows initializing a Person with a username that is not lower case.