Укажите относительную ширину двух встроенных «записей» в виде «текстового» виджета

Within a text widget? No, there is no direct support for relative widths. within a frame? yes. If you are putting them in a text widget (I presume, so you can scroll them) you have to manage the widths yourself. You can add a binding to the event of the text widget. This fires when the text widget changes size, and you can resize all the widgets at that point.

Проще всего положить их в фрейм с помощью grid , а затем поместить рамку в холст, чтобы вы могли ее прокручивать.

Вот пример:

import Tkinter as tk

class SampleApp(tk.Tk):
    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)
        self.canvas = tk.Canvas(self, width=200, highlightthickness=0)
        self.vsb = tk.Scrollbar(orient="vertical", command=self.canvas.yview)
        self.canvas.configure(yscrollcommand=self.vsb.set)
        self.vsb.pack(side="right", fill="y")
        self.canvas.pack(side="left", fill="both", expand=True)

        self.container = tk.Frame(self.canvas, borderwidth=0, highlightthickness=0)
        self.container.grid_columnconfigure(0, weight=1)
        self.container.grid_columnconfigure(1, weight=1)
        for i in range(30):
            e1 = tk.Entry(self.container)
            e2 = tk.Entry(self.container)
            e1.grid(row=i, column=0,sticky="ew")
            e2.grid(row=i, column=1,sticky="ew")
            e1.insert(0, "find %s" % i)
            e2.insert(0, "replace %s" % i)

        self.canvas.create_window((0,0), anchor="nw", window=self.container, tags="container")
        self.canvas.configure(scrollregion=self.canvas.bbox("all"))
        self.canvas.bind("", self.OnCanvasConfigure)

    def OnCanvasConfigure(self, event):
        self.canvas.itemconfigure("container", width=event.width)
        self.canvas.configure(scrollregion=self.canvas.bbox("all"))

if __name__ == "__main__":
    app = SampleApp()
    app.mainloop()