assigning values in python and perl

[J. Peng]

I just thought python's way of assigning value to a variable is really
different to other language like C,perl. :)

Below two ways (python and perl) are called "pass by reference", but
they get different results.
Yes I'm reading 'Core python programming', I know what happened, but
just a little confused about it.

$ cat t1.py
def test(x):
    x = [4,5,6]

a=[1,2,3]
test(a)
print a

$ python t1.py
[1, 2, 3]

$ cat t1.pl
sub test {
    my $ref = shift;
    @$ref = (4,5,6);
}

my @a = (1,2,3);
test(\@a);

print "@a";

$ perl t1.pl
4 5 6