Preferred method for "Assignment by value"

[hall.jeff]

As a relative new comer to Python, I haven't done a heck of a lot of
hacking around with it. I had my first run in with Python's quirky (to
me at least) tendency to assign by reference rather than by value (I'm
coming from a VBA world so that's the terminology I'm using). I was
surprised that these two cases behave so differently

test = [[1],[2]]
x = test[0]
x[0] = 5
test

>>[[5],[2]]

x = 1
test

>>>[[5],[2]]

x

>>1

Now I've done a little reading and I think I understand the problem...
My issue is, "What's the 'best practise' way of assigning just the
value of something to a new name?"

i.e.
test = [[1,2],[3,4]]
I need to do some data manipulation with the first list in the above
list without changing <test>
obviously x = test[0] will not work as any changes i make will alter
the original...
I found that I could do this:
x = [] + test[0]

that gets me a "pure" (i.e. unconnected to test[0] ) list but that
concerned me as a bit kludgy

Thanks for you time and help.

[castironpi]

On Apr 15, 3:51*pm, sturlamolden <sturlamol...@y ahoo.nowrote:

On Apr 15, 8:19 pm, hall.j...@gmail .com wrote:

Coming from VBA I have a tendency to think of everything as an
array...

Coding to much in Visual Basic, like Fortran 77, is bad for your mind.

The distinction you're looking for is:

VB:
set a= collection
a= collection

Every assignment is a 'set'.