My tkinter window looks very different on different computers (running on the same resolution!):

windows 8

windows 7

I want it to look like it does in the first one. Any ideas?

My code looks like this:

class Application():def __init__(self):self.app = Tk()self.app.wm_iconbitmap('.\data\spider.ico')self.app.wm_title("Spider Crawler")self.app.minsize(width=914, height=331)self.app.maxsize(width=914, height=331)mainmainleft = Frame(self.app)bottom = Frame(self.app)mainleft = Frame(mainmainleft)itemoptions = Frame(bottom)self.graph = multilist.McListBox(bottom)startn = Frame(mainleft)options = Frame(mainleft)hourcredits = Frame(mainleft)hoursoption = Frame(hourcredits)credits = Frame(hourcredits)allbuttons = Frame(mainleft)fstart = Frame(startn)bp = Frame(allbuttons)buttons = Frame(allbuttons)self.SchemaUpdate = BooleanVar()self.reset = BooleanVar()self.genuine = BooleanVar()self.buds = BooleanVar()self.bills = BooleanVar()self.unusual = BooleanVar()self.maxs = BooleanVar()self.bmoc = BooleanVar()self.salvage = BooleanVar()self.traded = BooleanVar()self.entryid = StringVar()self.clicked = Falsefor i in [self.reset, self.buds, self.unusual, self.maxs, self.salvage]:i.set(True)self.b = Button(fstart, text="START", command=self.start)c = Button(buttons, text="Steam", command=self.steam).pack(side=LEFT, padx=(0,7))d = Button(buttons, text="GotoBP", command=self.backpack).pack(side=LEFT)self.b.pack(side=LEFT)buttons.pack()self.var = StringVar(self.app)self.var.set("backpack.tf/profiles/")option = OptionMenu(bp, self.var, "backpack.tf/profiles/", "tf2items.com/profiles/", "tf2b.com/tf2/")option.config(width = 18)option.pack()bp.pack(side = BOTTOM)    self.box = Entry(startn, textvariable=self.entryid, fg = "gray")self.box.bind("<Button-1>", self.callback)self.box.insert(0, "Enter steamid")self.box.pack(side = TOP, anchor=N, padx =(5,25), pady = 10)Label(credits, text="Created by Akenne", font=("Times New Roman", 8)).pack(anchor = E, pady = (0,25))credits.pack(side=TOP, anchor=E)Label(hoursoption, text="Max Hours:").pack(side=LEFT, padx = (0,10))self.hours=IntVar()self.hours.set(250)Entry(hoursoption,textvariable=self.hours,width=5).pack(side=LEFT)hoursoption.pack(padx= (0,45))Checkbutton(options, text = "Reload item schema", variable = self.SchemaUpdate).pack(side=TOP, anchor=W, pady =(0, 3))Checkbutton(options, text = "Start with fresh id", variable = self.reset).pack(side=TOP, anchor=W)Checkbutton(itemoptions, text = "Only never traded items", variable = self.traded).pack(side=TOP, anchor=W)Checkbutton(itemoptions, text = "Genuines", variable = self.genuine).pack(side=TOP, anchor=W)Checkbutton(itemoptions, text = "Earbuds", variable = self.buds).pack(side=TOP, anchor=W)Checkbutton(itemoptions, text = "Bill's", variable = self.bills).pack(side=TOP, anchor=W)Checkbutton(itemoptions, text = "Unusuals", variable = self.unusual).pack(side=TOP, anchor=W)Checkbutton(itemoptions, text = "Max's items", variable = self.maxs).pack(side=TOP, anchor=W)Checkbutton(itemoptions, text = "BMOCs", variable = self.bmoc).pack(side=TOP, anchor=W)Checkbutton(itemoptions, text = "Salvaged crates", variable = self.salvage).pack(side=TOP, anchor=W)self.lbl = Label(fstart, text="0/0 found")self.lbl.pack(side = LEFT, anchor = W, padx = (20,30))fstart.pack(side=TOP)startn.pack(side=LEFT, anchor = W, padx = (10, 0))options.pack(side=LEFT, padx=(0,30), pady = (5,0))allbuttons.pack(side=LEFT, pady=(10,0), padx = (40,0))hourcredits.pack(side=LEFT, padx = (95,0), anchor = E)mainleft.pack(side = TOP, anchor = W)self.graph.container.pack(side = LEFT, anchor = W, pady = 10)itemoptions.pack(side=LEFT, anchor = E, padx=7)mainmainleft.pack(side = TOP, fill = X)bottom.pack(padx =10)self.app.mainloop()

Yes, tkinter applications will look different on different platforms. This is by design. When possible, Tkinter will use native widgets -- widgets provided by the OS. This means that Tkinter does not have ultimate control over every aspect of the GUI.

Under most circumstances this is the desired behavior. You want a button on Windows to look like a Windows button, and you want a button on OSX to look like an OSX button. This also means that you may get different buttons on Windows 7 vs Windows 8 -- tkinter is just using whatever the OS gives it, and Microsoft tends to tweak its widgets with every major revision.

Can you get the exact same look on all platforms? That depends. You can probably get nearly identical results on Windows 7 and 8 with a small amount of work. It will be very difficult to get the same look between Windows and Macintosh.

Unfortunately, these differences not only result in different looking widgets, but it can cause layout differences as well. For example, different platforms may have different fonts, different default border widths, and default margins and padding. All of this contributes to the final layout of a window.

In your specific case, the most obvious difference is that Windows 7 is using a slightly smaller font than Windows 8. That alone can have a big effect on layout. It also appears that the McListBox widget has a larger border around it on windows 7 than on windows 8. I don't know anything about that widget, so it could have different defaults based on the platform.

Most of these problems can be resolved by using explicit values for borders, padding, fonts, etc. Sometimes it takes a little experimentation.