[Tutor] Stopping evalualtion of inner Lists/ tuples

[Remco Gerlich]

On Tue, Jan 23, 2001 at 05:42:14AM -0500, Sharriff Aina wrote:
> Hi Guys!
> 
> Considering the following:
> 
> tab1 = {"feld1": "varchar", "feld2": "varchar"}
> tab2 = {"feld3": "varchar", "feld4": "varchar"}
> virtuallist = [tab1, tab2]

Now, virtuallist stores *references* to tab1 and tab2. It doesn't know their
names.

> >>> vlist
> [{'feld2': 'varchar', 'feld1': 'varchar'}, {'feld3': 'varchar', 'feld4':
> 'varchar'}]
> >>> for x in vlist:
>         print x
>         
> {'feld2': 'varchar', 'feld1': 'varchar'}
> {'feld3': 'varchar', 'feld4': 'varchar'}
> 
> >>> for x in vlist:
>         print `x`
> 
> {'feld2': 'varchar', 'feld1': 'varchar'}
> {'feld3': 'varchar', 'feld4': 'varchar'}
> 
> How can I stop the evaluation of the innner List or tuple?

They were already evaluated at the "tab1 = " line. vlist keeps references to
these lists, but doesn't know that there happen to be names for these lists.

I would like to
> have
> 
> for tables in virtuallist:
>     print tables
> 
> >>> tab1
>         tab2

You probably want to make a dictionary instead of a list.

Try:

virtuallist = {'tab1': tab1, 'tab2': tab2 }
for name, table in virtuallist.items():
   print name, table
   


Hope this helps.

-- 
Remco Gerlich