I have tried unsuccessfully several times to get programs to remember settings after they've been destroyed. A large reason for that is because I don't have an example code to work off of. Below I have a simple program I wrote. I'd like it so that it both remembers the position of the scale, and the contents of the text widget upon restarting the program开发者_C百科. I hate having to ask someone to write code for me, but I'm honestly stuck.
I'm using Python 2.6.5 on Windows 7, BTW.
Code:
import Tkinter
class simpleapp_tk(Tkinter.Tk):
def __init__(self,parent):
Tkinter.Tk.__init__(self,parent)
self.parent = parent
self.initialize()
def initialize(self):
self.sclX = Tkinter.Scale(self, from_=0, to=100, orient='horizontal',resolution=1,command=self.A)
self.sclX.pack(ipadx=75)
self.labelVar = Tkinter.StringVar()
self.label = Tkinter.Label(self,textvariable=self.labelVar)
self.label.pack(ipadx=75)
self.frame = Tkinter.Frame(self,relief='ridge',borderwidth=4)
self.frame.pack()
self.LVariable = Tkinter.StringVar()
self.s = Tkinter.Scrollbar(self.frame)
self.L = Tkinter.Text(self.frame,borderwidth=0,font=('Arial', 10),width=30, height=15)
self.s.config(command=self.L.yview,elementborderwidth=1)
self.L.grid(column=0,row=0,sticky='EW')
self.s.grid(column=1,row=0,sticky='NSEW')
def A(self, event):
self.labelVar.set(100 - self.sclX.get())
if __name__ == "__main__":
app = simpleapp_tk(None)
app.mainloop()
It's not a matter of asking people to write code for you but knowing what to look for, you could write your own code after that!
I think remembering settings like you describe is commonly done in two ways:
- Config file
- Registry entries
You can then read in the stored value from either the config file/registry whenever your program loads, and adjust parameters to match.
So now you go look up how you read/write files/registry entries and you are set!
Depending on how you prefer to store settings you can also look into things like Shelve and Pickle/cPickle. I personally prefer Shelve because I tend to use dictionaries as settings containers and Shelve lets me store those as is. Full documentation available here: http://docs.python.org/library/shelve.html
Your previous question where you had difficulty saving state using cPickle was a good start.
I have added a couple of methods to your code and it will now save and load the data in the Scale
and Text
widgets using the pickle
module. I've never used Shelve - that sounds like it would be easier based on what g.d.d.c says in his(?) answer.
I store the widget values in a dictionary, then pickle the dictionary.
import Tkinter
import pickle
class simpleapp_tk(Tkinter.Tk):
def __init__(self, parent=None):
Tkinter.Tk.__init__(self, parent)
self.parent = parent
self.initialize()
self.load_data()
self.protocol("WM_DELETE_WINDOW", self.save_data)
def initialize(self):
self.sclX = Tkinter.Scale(self, from_=0, to=100, orient='horizontal',
resolution=1,command=self.update_label)
self.sclX.pack(ipadx=75)
self.labelVar = Tkinter.StringVar()
self.label = Tkinter.Label(self,textvariable=self.labelVar)
self.label.pack(ipadx=75)
self.frame = Tkinter.Frame(self,relief='ridge',borderwidth=4)
self.frame.pack()
#self.LVariable = Tkinter.StringVar()
self.s = Tkinter.Scrollbar(self.frame)
self.L = Tkinter.Text(self.frame, borderwidth=0, font=('Arial', 10),
width=30, height=15)
self.s.config(command=self.L.yview, elementborderwidth=1)
self.L.grid(column=0, row=0, sticky='EW')
self.s.grid(column=1, row=0, sticky='NSEW')
def update_label(self, event):
self.labelVar.set(100 - self.sclX.get())
def save_data(self):
data = {'scale': self.sclX.get(), 'text': self.L.get('1.0', 'end')}
with file('config.data', 'wb') as f:
pickle.dump(data, f)
self.destroy()
def load_data(self):
try:
with file('config.data', 'rb') as f:
data = pickle.load(f)
self.sclX.set(data['scale'])
self.L.insert("end", data['text'])
except IOError:
# no config file exists
pass
if __name__ == "__main__":
app = simpleapp_tk()
app.mainloop()
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