Going crazy...

Jan Danielsson

Hello all,

I'm 100% sure that I saw an example which looked something like this
recently:

a=(1, 2, 3, 4, 5, 6)
b=(2, 3, 6)
a - b

(1, 4, 5)

The only new language I have been involved in lately is Python. Is my
memory failing me, or have I seen such an Python-example somewhere? If
so: Where; or more importantly: How does it work?

I just tried typing the above in Python, and it - obviously - doesn't
work, so it must be some other syntax.

Jul 19 '05 #1

Gary Herron

Jan Danielsson wrote:

Hello all,

I'm 100% sure that I saw an example which looked something like this
recently:

a=(1, 2, 3, 4, 5, 6)
b=(2, 3, 6)
a - b

(1, 4, 5)

The only new language I have been involved in lately is Python. Is my
memory failing me, or have I seen such an Python-example somewhere? If
so: Where; or more importantly: How does it work?

I just tried typing the above in Python, and it - obviously - doesn't
work, so it must be some other syntax.

Not with tuples, lists or dictionaries. However a more recent addition
to the language is Sets, and they support set differences:

from sets import Set
Set([1,2,3,4,5,6]) - Set([2,3,6])

Set([1, 4, 5])
Gary Herron

Jul 19 '05 #2

Irmen de Jong

Jan Danielsson wrote:

Hello all,

I'm 100% sure that I saw an example which looked something like this
recently:

a=(1, 2, 3, 4, 5, 6)
b=(2, 3, 6)
a - b
(1, 4, 5)

The only new language I have been involved in lately is Python. Is my
memory failing me, or have I seen such an Python-example somewhere? If
so: Where; or more importantly: How does it work?

I just tried typing the above in Python, and it - obviously - doesn't
work, so it must be some other syntax.

Try sets:

a=set([1,2,3,4,5,6])
b=set([2,3,6])
a-b set([1, 4, 5])

--Irmen

Jul 19 '05 #3

Chinook

On Mon, 13 Jun 2005 20:52:43 -0400, Gary Herron wrote
(in article <42**************@islandtraining.com>):

Jan Danielsson wrote:

Hello all,

I'm 100% sure that I saw an example which looked something like this
recently:

> a=(1, 2, 3, 4, 5, 6)
> b=(2, 3, 6)
> a - b
>
>

(1, 4, 5)

The only new language I have been involved in lately is Python. Is my
memory failing me, or have I seen such an Python-example somewhere? If
so: Where; or more importantly: How does it work?

I just tried typing the above in Python, and it - obviously - doesn't
work, so it must be some other syntax.

Not with tuples, lists or dictionaries. However a more recent addition
to the language is Sets, and they support set differences:

>>> from sets import Set
>>> Set([1,2,3,4,5,6]) - Set([2,3,6])

Set([1, 4, 5])
Gary Herron

Looks like something that might be part of an example of class operator
overloading??? But I'm not far enough along to quickly show a sample if such
is possible.

Lee C

Jul 19 '05 #4

Jan Danielsson

Gary Herron wrote:
[---]

I just tried typing the above in Python, and it - obviously - doesn't
work, so it must be some other syntax.

Not with tuples, lists or dictionaries. However a more recent addition
to the language is Sets, and they support set differences:

from sets import Set
Set([1,2,3,4,5,6]) - Set([2,3,6])

Set([1, 4, 5])

That's it! Thanks; I knew I had seen it. That's a pretty cool
feature; which I have use for in a library I'm writing.

Jul 19 '05 #5

Scott David Daniels

Jan Danielsson wrote:

Gary Herron wrote:

... a more recent addition to the language is Sets, ...

>from sets import Set
>Set([1,2,3,4,5,6]) - Set([2,3,6])

Set([1, 4, 5])

If you are using 2.4 or later, you can simply use "set" without
importing anything.

set(['apple', 'orange', 5]) - set([5])

--Scott David Daniels
Sc***********@Acm.Org

Jul 19 '05 #6