On Tue, 29 Mar 2005 22:32:59 +0200, Pierre Quentel <[EMAIL PROTECTED]> wrote:
Instead of indexing self.lab by strings, you can index them by the
attributes themselves : self.lab[self.i], and change line 23 into
for var in (self.s, self,i)
I really think this is asking for trouble: I suppose that the i and s
attributes are meant to change at some point in the future, and you're mapping
their *values* to the corresponding labels. So if the value changes, you won't
be able to get the label again.
For your example, I wouldn't have used the "text" option in the
definition of the labels, then "textvariable" in the callback method
(procedi) ; I would have used only "text" and no IntVar or StringVar,
just an integer and a string :
I would have done exactly the contrary, as it is far more easier to use.
Using the textvariable option in Label's does not require you to remember the
labels, but only the variables used to hold their contents. I'd also use two
mappings: the first mapping a name to a Tkinter variable for the label
variables, and the second for the values to give to these variables later.
Here is my version of the class code:
class MiaApp:
def __init__(self, genitore):
self.mioGenitore = genitore
## Mapping for variables
self.variables = {
"i" : StringVar(),
"s" : StringVar()
}
## Mapping for future variable values
self.values = {
"i" : 42,
"s" : "Baobab"
}
## Now, create the labels
for var in self.variables.values():
## Default text
var.set("[vuota]")
## Create label
lb = Label(self.mioGenitore, width=30, relief=RIDGE, textvariable=var)
lb.pack()
## The button is no more remembered in an attribute, as it does not
seem to be needed
but = Button(self.mioGenitore, text = "Vai!", command = self.procedi)
but.pack()
def procedi(self):
## Just change the variable values
for varName in self.variables.keys():
self.variables[varName].set(self.values[varName])
Note that I only used StringVar's: since the variable holds the *text* for a
Label, it is not a good idea to use anything else. I tend to use IntVar,
BooleanVar or DoubleVar only when I'm sure it won't ever be set to anything
else than an integer, a boolean or a float respectively. So for Label and Entry
text variables, I always use a StringVar. In spite of their name, these
variable can actually hold anything; you will just get the value you've given
to them as text rather than as their original type:
v = StringVar()
v.set(42)
v.get()
'42'
So if you want to get the integer back, you'll need to convert the value
explicitely. This is in fact what is done by Tkinter when using an IntVar, but
by doing it yourself, you'll be able to decide what to do if the conversion
fails instead of just getting a generic TclError.
HTH
--
python -c 'print "".join([chr(154 - ord(c)) for c in
"U(17zX(%,5.z^5(17l8(%,5.Z*(93-965$l7+-"])'
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