Python reference model -

Python reference model -

i have hard time understand python reference model

def changer(a,b): = 2 b[0] = 'spam' x = 1 l = [1,2] changer(x,l) x,l (1,['spam',2])

here comes question, assignment b[0] = 'spam' : want know how python modify mutable object in way(instead of create new string objects , link variable b object not impact original object pointed l)

thanks

a , b both references objects.

when reassign a alter object a referencing.

when reassign b[0] reassigning reference contained within b. b still references same list object did originally, list passed changer function.

python