[IronPython] Newbie: convert string to python expression??
Michael Foord
fuzzyman at voidspace.org.uk
Tue Dec 16 16:28:36 CET 2008
Oh - and Windows Forms has a Keys enumeration so that you don't have to
rely on the underlying value of the event key property.
from System.Windows.Forms import Keys
if e.Key == Keys.Enter:
(or something like that - check out the MSDN documentation for the
enumeration.)
Michael Foord
Michael Foord wrote:
>
> context = {}
>
> def inputBox_KeyDown(s, e):
> root.message.Text = ''
> key = e.Key.value__
> result = root.inputBox.Text
> if key == 3: #If 'Enter' key is pressed
> try:
> try:
> root.message.Text = eval(result)
> except SyntaxError:
> exec result in context
> except Exception, e:
> print 'Unhandled exception', e
>
> Note the "exec result in context" and my suggested changes to your
> exception handling.
>
> Michael
>
>
> xkrja wrote:
>> Thanks for the reply.
>>
>> Below is a snippet of what I've got:
>>
>> def inputBox_KeyDown(s, e):
>> root.message.Text = ''
>> key = e.Key.value__
>> result = root.inputBox.Text
>> if key == 3: #If 'Enter' key is pressed
>> try:
>> root.message.Text = eval(result)
>> except:
>> exec result
>> root = Application.Current.LoadRootVisual(UserControl(),
>> "app.xaml")
>> sys.stdout = Writer(root.message)
>>
>> root.inputBox.KeyDown += inputBox_KeyDown
>>
>> Can't I just put everthing that is evaluated or executed in some kind of
>> global scope so that they can be accessed just like in the console?
>> If not:
>> I looked a little at dictionaries but didn't really understand how to
>> use
>> them in this case? Can someone give me a short example that can be
>> used for
>> my case?
>>
>> Once again, thanks for all help!
>>
>>
>> Michael Foord-5 wrote:
>>
>>> You've snipped the code so I can't see it exactly, but I'm pretty
>>> sure you are doing this inside a method. This will create a new
>>> 'scope' every time you enter the method and so you are creating a
>>> local variable that disappears when you exit the method.
>>>
>>> When you exec you can provide a dictionary as a context for the
>>> execution to happen in. If you store this as an instance member and
>>> re-use the same execution context every time then changes will be
>>> 'remembered'.
>>>
>>> Michael
>>>
>>>
>>
>>
>
>
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