Problem with class variables

[Dag]

I have a problem which is probaly very simple to solve, but I can't
find a nice solution.
I have the following code

class Test:
def __init__(self):
self.a=[1,2,3,4]
self.b=self.a
def swap(self):
self.a[0],self.a[3]=self.a[3],self.a[0]
def prnt(self):
print self.a
print self.b
c=Test()
c.swap()
c.prnt()

which returns
[4,2,3,1]
[4,2,3,1]

Now I understand why it is doing this, but it's not what I want. How to
I get it to return
[4,2,3,1]
[1,2,3,4]

Dag

[Marc 'BlackJack' Rintsch]

Re: Problem with class variables

In <slrnf0nfph.8f9 .f98dawa@remote 1.student.chalm ers.se>, Dag wrote:

I have a problem which is probaly very simple to solve, but I can't
find a nice solution.
I have the following code
>
class Test:
def __init__(self):
self.a=[1,2,3,4]
self.b=self.a

self.b = list(self.a)

BTW this is about instance variable, not class variables.

Ciao,
Marc 'BlackJack' Rintsch

[kyosohma@gmail.com]

Re: Problem with class variables

On Mar 29, 8:43 am, Marc 'BlackJack' Rintsch <bj_...@gmx.net wrote:

In <slrnf0nfph.8f9 .f98d...@remote 1.student.chalm ers.se>, Dag wrote:

I have a problem which is probaly very simple to solve, but I can't
find a nice solution.
I have the following code

>

class Test:
def __init__(self):
self.a=[1,2,3,4]
self.b=self.a

>
self.b = list(self.a)
>
BTW this is about instance variable, not class variables.
>
Ciao,
Marc 'BlackJack' Rintsch

One of the many ways to do this:

class Test:
def __init__(self):
self.a=[1,2,3,4]
#self.b=self.a
def swap(self):
self.a[0],self.a[3]=self.a[3],self.a[0]
return self.a
def prnt(self):
print self.a
x = self.swap()
print x

c=Test()
c.prnt()


Mike

[=?ISO-8859-15?Q?Thomas_Kr=FCger?=]

Re: Problem with class variables

Dag schrieb:

I have a problem which is probaly very simple to solve, but I can't
find a nice solution.
I have the following code
>
class Test:
def __init__(self):
self.a=[1,2,3,4]
self.b=self.a
def swap(self):
self.a[0],self.a[3]=self.a[3],self.a[0]
def prnt(self):
print self.a
print self.b
c=Test()
c.swap()
c.prnt()
>
which returns
[4,2,3,1]
[4,2,3,1]
>
Now I understand why it is doing this, but it's not what I want. How to
I get it to return
[4,2,3,1]
[1,2,3,4]
>
Dag

Use a copy of self.a:
self.b = self.a[:]

Thomas