importing class

[gmarkowsky]

Hi all,

I'm trying to import a class from a module. The class looks like this:
class App:

def __init__(self, master):

frame = Frame(master)
frame.pack()

self.button = Button(frame, text=text_1, command= self.comm_1)
self.button.pack(side=LEFT)

self.hi_there = Button(frame, text=text_2, command=self.comm_2)
self.hi_there.pack(side=LEFT)

def comm_1(self):
command1()
root.quit()

def comm_2(self):
command2()
root.quit()

It's supposed to just make a Tkinter window with two choices. The
problem is that when I import it from a module, I get the following
error:

NameError: global name 'Frame' is not defined

But when I copy and paste it into the file, it works. Can anyone tell
me what's wrong?

Greg

 

[Marc 'BlackJack' Rintsch]

Hi all,

I'm trying to import a class from a module. The class looks like this:
class App:

def __init__(self, master):

frame = Frame(master)
frame.pack()

self.button = Button(frame, text=text_1, command= self.comm_1)
self.button.pack(side=LEFT)

self.hi_there = Button(frame, text=text_2, command=self.comm_2)
self.hi_there.pack(side=LEFT)

def comm_1(self):
command1()
root.quit()

def comm_2(self):
command2()
root.quit()

It's supposed to just make a Tkinter window with two choices. The
problem is that when I import it from a module, I get the following
error:

NameError: global name 'Frame' is not defined

But when I copy and paste it into the file, it works. Can anyone tell
me what's wrong?

Yes, the global name `Frame` is not defined. `Frame` is a name in the
`Tkinter` module and you have to import it to reference it. Add the
following import statement to your file:

from Tkinter import Frame, Button

You use `Button` too and this also lives in the `Tkinter` module.

Ciao,
Marc 'BlackJack' Rintsch

 

[Dennis Lee Bieber]

It's supposed to just make a Tkinter window with two choices. The
problem is that when I import it from a module, I get the following
error:

NameError: global name 'Frame' is not defined

But when I copy and paste it into the file, it works. Can anyone tell
me what's wrong?

Probably the simple fact that your "file" likely has all the imports
for Tkinter defined. The module that you are importing needs to have
those imports inside it -- imported modules do not have visibility of
names defined in the importING file.
--
Wulfraed Dennis Lee Bieber KD6MOG
(e-mail address removed) (e-mail address removed)
HTTP://wlfraed.home.netcom.com/
(Bestiaria Support Staff: (e-mail address removed))
HTTP://www.bestiaria.com/

 

[gmarkowsky]

Yep, that fixed it. Many thanks.

Greg

Probably the simple fact that your "file" likely has all the imports
for Tkinter defined. The module that you are importing needs to have
those imports inside it -- imported modules do not have visibility of
names defined in the importING file.
--
Wulfraed Dennis Lee Bieber KD6MOG
(e-mail address removed) (e-mail address removed)
HTTP://wlfraed.home.netcom.com/
(Bestiaria Support Staff: (e-mail address removed))
HTTP://www.bestiaria.com/

 

[gmarkowsky]

Thanks, I got that part. The problem I'm still having is that it's not
seeing things like text_1, which are defined in the program. How can I
make it see that?

Another question I should ask is whether I should even bother doing
this. That is, it seems that the elegant and approved way of doing this
kind of thing may be to put a class in a module and then just use the
module over and over again in programs. I'm making a few GUIs which
present two options and ask the user to chose one, so I thought I could
just do it this way. Of course I could very easily just copy and paste
the class into each file, but that seems silly. I haven't had any
trouble using modules for functions, but for classes it is not working
right so far, and I'm having trouble finding examples to follow.

Greg

 

[Steve Holden]

Thanks, I got that part. The problem I'm still having is that it's not
seeing things like text_1, which are defined in the program. How can I
make it see that?

Your module is intended to work with many different main programs, so it
shouldn't make any assumptions about the names that the main program
uses for things. That would be rather bad programming style ("rigind
coupling" is something to be avoided where possible). I wouldn't call
that class App just because it's misleading: maybe you could change the
name to YesNo, or Choice, or something more indicative of its function?

You could pass text_1 and text_2 as arguments to the class's __init__
method - that way you could just use them directly.

Another question I should ask is whether I should even bother doing
this. That is, it seems that the elegant and approved way of doing this
kind of thing may be to put a class in a module and then just use the
module over and over again in programs. I'm making a few GUIs which
present two options and ask the user to chose one, so I thought I could
just do it this way. Of course I could very easily just copy and paste
the class into each file, but that seems silly. I haven't had any
trouble using modules for functions, but for classes it is not working
right so far, and I'm having trouble finding examples to follow.

Seems like parameterization is the thing you are missing. Change the
__init__ method declaration to

def __init__(self, master, text_1="OK", text_2="Cancel"):
...

leaving the rest of the code the same. (Though I note your module also
fails to define a "command1" and "command2" function, this may just be
because you are only quoting partial code).

Then in your main program create the object with

myDialog = YesNo(master, "Yes", "No")

Looks like you are new to Python - perseverre and you will pick it up
quite quickly!

regards
Steve

 

[gmarkowsky]

Thanks for your help. Actually my idea was that command1 and command2
would be defined within the program, not the module, as I would have
different choices in different programs. Should I pass them in as a
parameter too?

Greg

 

[Steve Holden]

Thanks for your help. Actually my idea was that command1 and command2
would be defined within the program, not the module, as I would have
different choices in different programs. Should I pass them in as a
parameter too?

It would seem to be the only way to tell your object which callbacks to
call!

regards
Steve