What is the output of the following Python code?
class A:
def __init__{self}:
self.v = 1
def change(self):
self.v += 1a = A()
a.change()
getattr(a, 'change')()
print(a.v)
a.change() increments v to 2. getattr(a, 'change') retrieves bound method change, calling it increments v to 3.
What will be the output of print(hasattr(A(), 'x')) for:
class A:
def __init__{self}:
self.x = 10
def clear(self):
del self.xa = A()
a.clear()
print(1 if hasattr(a, 'x') else 0)
del self.x deletes instance attribute x. hasattr(a, 'x') returns False (0).
Which built-in function returns a dictionary containing the instance attributes of an object?
vars(obj) returns obj.__dict__, which holds the object's instance attributes in a dictionary.
Consider the following snippet:
class Test:
passt = Test()
t.a = 5
t.b = 10
setattr(t, 'c', 15)
print(sum(t.__dict__.values()))
t.__dict__ contains {'a': 5, 'b': 10, 'c': 15}. Sum of values = 5 + 10 + 15 = 30.
What is the output of the following Python code?
class Student:
def __init__{self, name, marks}:
self.name = name
self.marks = marks
def __str__{self}:
return f'{self.name}:{self.marks}'s = Student('Bob', 90)
print(str(s))
The __str__ method returns 'Bob:90', which is invoked by str(s) or print(s).