Hi All:
Here's a piece of Python code and it's output. The output that Python
shows is not as per my expectation. Hope someone can explain to me this
behaviour:
[code]
class MyClass:
def __init__(self, myarr=[]):
self.myarr = myarr
myobj1 = MyClass()
myobj2 = MyClass()
myobj1.myarr += [1,2,3]
myobj2.myarr += [4,5,6]
print myobj1.myarr
print myobj2.myarr
[/code]
The output is:
[1, 2, 3, 4, 5, 6]
[1, 2, 3, 4, 5, 6]
Why do myobj1.myarr and myobj2.myarr point to the same list? The
default value to __init__ for the myarr argument is [], so I expect
that every time an object of MyClass is created, a new empty list is
created and assigned to myarr, but it seems that the same empty list
object is assigned to myarr on every invocation of MyClass.__init__
It this behaviour by design? If so, what is the reason, as the
behaviour I expect seems pretty logical.
Thanks.
Vaibhav
--
http://mail.python.org/mailman/listinfo/python-list
