Hello All,
I originally posted this to the help list, but I wanted to try a broader
audience. Its so bizarre, that it may take some discourse to understand what
is going on.
Far below are two alternative methods I have made inside a class. In "method1"
I create a name called "passWindow.res ult" and use it in the "ok()" function.
In "method2", I simply call this name "result".
Matt Cowles gave this explanation:[color=blue]
> The important difference is that you assign to the variable result
> later in the function. If a variable isn't assigned to in a function,
> Python looks for it in enclosing namespaces:[/color]
If I understand Matt's answer, "ask_for_passwo rd(self,message )", should be the
enclosing namespace for "ok()". So I am still confused: notice how I defined
"passWindow " on the line preceding the "result=Non e" (method2) or
"passWindow.res ult=None" (method1) statments. I haven't defined "passWindow "
before I defined it in the "get_password(s elf)" method, i.e. "passWindow ",
like "result" and "passWindow.res ult", is not part of the global name space
or any other enclosing namespace beyond the "get_password(s elf)" method.
Testing Matt's explanation, I began a fresh CLI session (using the same python
executable used for my program). The session is cut and pasted from my
terminal:
% python
Python 2.3.3 (#2, Feb 17 2004, 11:45:40)
[GCC 3.3.2 (Mandrake Linux 10.0 3.3.2-6mdk)] on linux2
Type "help", "copyright" , "credits" or "license" for more information.[color=blue][color=green][color=darkred]
>>> def outer():[/color][/color][/color]
.... def inner():
.... print bob
.... bob = "wuzzup?"
.... inner()
....[color=blue][color=green][color=darkred]
>>> outer()[/color][/color][/color]
wuzzup?
This works as I expect and in accord with Matt's explanation and the Laws of
Common Sense, but it appears to be entirely inconsistent with the behavior of
"method2" below. Thus, I am completely bewildered.
I have pasted the methods below (sorry they are so long, but I didn't want
to alter them--maybe clues lie within).
-----
# method1
############### ############### ############### ############### #########
# get_password(se lf)
############### ############### ############### ############### #########
def ask_for_passwor d(self, message):
def cancel():
passWindow.dest roy()
def ok():
# WORKS FINE!
print passWindow.resu lt
pw = passEntry.get()
if len(pw):
passWindow.resu lt = pw
passWindow.dest roy()
message = "\n" + message + "\n"
# make a new top level for the pass window
passWindow = Toplevel(self.g et_mainWindow() )
passWindow.resu lt = None
# title it something meaningful
passWindow.titl e("passerby - Password Entry")
# - will use the main view (view #0) to own the password entry
# this will help the user remember what he's doing
# - need to show the main view
self.get_mainWi ndow().deiconif y()
# - set ownership of the passWindow to main view
passWindow.tran sient(self.get_ mainWindow())
# setting the geometry of the passWindow
# pass_x = anEvent.x_root - 50
# pass_y = anEvent.y_root - 50
passWindow.geom etry("400x180+5 0+50")
# - don't let user change our beautiful window
passWindow.resi zable(0,0)
# the entry label and field
passLabel = Label(passWindo w, text=message)
passEntry = Entry(passWindo w)
passEntry.confi gure(width=48)
passEntry.confi g(show="*")
passEntry.bind( "<Return>", ok)
cancelButton = Button(passWind ow, text="Cancel", command=cancel)
okButton = Button(passWind ow, text="OK", command=ok)
passLabel.pack( )
passEntry.pack( )
cancelButton.pa ck()
okButton.pack()
passEntry.focus _set()
passWindow.grab _set()
self.get_tk().w ait_window(pass Window)
return passWindow.resu lt
-----
# method2
############### ############### ############### ############### #########
# get_password(se lf)
############### ############### ############### ############### #########
def ask_for_passwor d(self, message):
def cancel():
passWindow.dest roy()
def ok():
# GETS ERROR!
print result
pw = passEntry.get()
if len(pw):
passWindow.resu lt = pw
passWindow.dest roy()
message = "\n" + message + "\n"
# make a new top level for the pass window
passWindow = Toplevel(self.g et_mainWindow() )
result = None
# title it something meaningful
passWindow.titl e("passerby - Password Entry")
# - will use the main view (view #0) to own the password entry
# this will help the user remember what he's doing
# - need to show the main view
self.get_mainWi ndow().deiconif y()
# - set ownership of the passWindow to main view
passWindow.tran sient(self.get_ mainWindow())
# setting the geometry of the passWindow
# pass_x = anEvent.x_root - 50
# pass_y = anEvent.y_root - 50
passWindow.geom etry("400x180+5 0+50")
# - don't let user change our beautiful window
passWindow.resi zable(0,0)
# the entry label and field
passLabel = Label(passWindo w, text=message)
passEntry = Entry(passWindo w)
passEntry.confi gure(width=48)
passEntry.confi g(show="*")
passEntry.bind( "<Return>", ok)
cancelButton = Button(passWind ow, text="Cancel", command=cancel)
okButton = Button(passWind ow, text="OK", command=ok)
passLabel.pack( )
passEntry.pack( )
cancelButton.pa ck()
okButton.pack()
passEntry.focus _set()
passWindow.grab _set()
self.get_tk().w ait_window(pass Window)
return result
--
James Stroud, Ph.D.
UCLA-DOE Institute for Genomics and Proteomics
611 Charles E. Young Dr. S.
MBI 205, UCLA 951570
Los Angeles CA 90095-1570
I originally posted this to the help list, but I wanted to try a broader
audience. Its so bizarre, that it may take some discourse to understand what
is going on.
Far below are two alternative methods I have made inside a class. In "method1"
I create a name called "passWindow.res ult" and use it in the "ok()" function.
In "method2", I simply call this name "result".
Matt Cowles gave this explanation:[color=blue]
> The important difference is that you assign to the variable result
> later in the function. If a variable isn't assigned to in a function,
> Python looks for it in enclosing namespaces:[/color]
If I understand Matt's answer, "ask_for_passwo rd(self,message )", should be the
enclosing namespace for "ok()". So I am still confused: notice how I defined
"passWindow " on the line preceding the "result=Non e" (method2) or
"passWindow.res ult=None" (method1) statments. I haven't defined "passWindow "
before I defined it in the "get_password(s elf)" method, i.e. "passWindow ",
like "result" and "passWindow.res ult", is not part of the global name space
or any other enclosing namespace beyond the "get_password(s elf)" method.
Testing Matt's explanation, I began a fresh CLI session (using the same python
executable used for my program). The session is cut and pasted from my
terminal:
% python
Python 2.3.3 (#2, Feb 17 2004, 11:45:40)
[GCC 3.3.2 (Mandrake Linux 10.0 3.3.2-6mdk)] on linux2
Type "help", "copyright" , "credits" or "license" for more information.[color=blue][color=green][color=darkred]
>>> def outer():[/color][/color][/color]
.... def inner():
.... print bob
.... bob = "wuzzup?"
.... inner()
....[color=blue][color=green][color=darkred]
>>> outer()[/color][/color][/color]
wuzzup?
This works as I expect and in accord with Matt's explanation and the Laws of
Common Sense, but it appears to be entirely inconsistent with the behavior of
"method2" below. Thus, I am completely bewildered.
I have pasted the methods below (sorry they are so long, but I didn't want
to alter them--maybe clues lie within).
-----
# method1
############### ############### ############### ############### #########
# get_password(se lf)
############### ############### ############### ############### #########
def ask_for_passwor d(self, message):
def cancel():
passWindow.dest roy()
def ok():
# WORKS FINE!
print passWindow.resu lt
pw = passEntry.get()
if len(pw):
passWindow.resu lt = pw
passWindow.dest roy()
message = "\n" + message + "\n"
# make a new top level for the pass window
passWindow = Toplevel(self.g et_mainWindow() )
passWindow.resu lt = None
# title it something meaningful
passWindow.titl e("passerby - Password Entry")
# - will use the main view (view #0) to own the password entry
# this will help the user remember what he's doing
# - need to show the main view
self.get_mainWi ndow().deiconif y()
# - set ownership of the passWindow to main view
passWindow.tran sient(self.get_ mainWindow())
# setting the geometry of the passWindow
# pass_x = anEvent.x_root - 50
# pass_y = anEvent.y_root - 50
passWindow.geom etry("400x180+5 0+50")
# - don't let user change our beautiful window
passWindow.resi zable(0,0)
# the entry label and field
passLabel = Label(passWindo w, text=message)
passEntry = Entry(passWindo w)
passEntry.confi gure(width=48)
passEntry.confi g(show="*")
passEntry.bind( "<Return>", ok)
cancelButton = Button(passWind ow, text="Cancel", command=cancel)
okButton = Button(passWind ow, text="OK", command=ok)
passLabel.pack( )
passEntry.pack( )
cancelButton.pa ck()
okButton.pack()
passEntry.focus _set()
passWindow.grab _set()
self.get_tk().w ait_window(pass Window)
return passWindow.resu lt
-----
# method2
############### ############### ############### ############### #########
# get_password(se lf)
############### ############### ############### ############### #########
def ask_for_passwor d(self, message):
def cancel():
passWindow.dest roy()
def ok():
# GETS ERROR!
print result
pw = passEntry.get()
if len(pw):
passWindow.resu lt = pw
passWindow.dest roy()
message = "\n" + message + "\n"
# make a new top level for the pass window
passWindow = Toplevel(self.g et_mainWindow() )
result = None
# title it something meaningful
passWindow.titl e("passerby - Password Entry")
# - will use the main view (view #0) to own the password entry
# this will help the user remember what he's doing
# - need to show the main view
self.get_mainWi ndow().deiconif y()
# - set ownership of the passWindow to main view
passWindow.tran sient(self.get_ mainWindow())
# setting the geometry of the passWindow
# pass_x = anEvent.x_root - 50
# pass_y = anEvent.y_root - 50
passWindow.geom etry("400x180+5 0+50")
# - don't let user change our beautiful window
passWindow.resi zable(0,0)
# the entry label and field
passLabel = Label(passWindo w, text=message)
passEntry = Entry(passWindo w)
passEntry.confi gure(width=48)
passEntry.confi g(show="*")
passEntry.bind( "<Return>", ok)
cancelButton = Button(passWind ow, text="Cancel", command=cancel)
okButton = Button(passWind ow, text="OK", command=ok)
passLabel.pack( )
passEntry.pack( )
cancelButton.pa ck()
okButton.pack()
passEntry.focus _set()
passWindow.grab _set()
self.get_tk().w ait_window(pass Window)
return result
--
James Stroud, Ph.D.
UCLA-DOE Institute for Genomics and Proteomics
611 Charles E. Young Dr. S.
MBI 205, UCLA 951570
Los Angeles CA 90095-1570
