Laptop booking system (tkinter)

import tkinter
from tkinter import messagebox


class Body:

    def __init__(self, master):
        self.rows = 7
        self.columns = 5
        self.master = master
        self.mainframe = tkinter.Frame(self.master, bg="white")     # building the grid
        self.mainframe.pack(fill=tkinter.BOTH, expand=True)         # packing the grid for use

        self.build_grid()                                           # calling the config function
        self.build_banners()


    def build_grid(self):                                           # method for configuring the grid,
        self.mainframe.columnconfigure(0, weight=1)                 # setting up amount of rows and columns
        self.mainframe.columnconfigure(1, weight=1)
        self.mainframe.columnconfigure(2, weight=1)
        self.mainframe.columnconfigure(3, weight=1)
        self.mainframe.columnconfigure(4, weight=1)
        self.mainframe.columnconfigure(5, weight=1)
        self.mainframe.columnconfigure(6, weight=1)
        self.mainframe.rowconfigure(0, weight=1)                    
        self.mainframe.rowconfigure(1, weight=1)
        self.mainframe.rowconfigure(2, weight=1)
        self.mainframe.rowconfigure(3, weight=1)
        self.mainframe.rowconfigure(4, weight=1)


# ignore this method
    def build_banner(self):
        banner = tkinter.Label(
            self.mainframe,
            bg="red",
            text="{}{}".format(self.row, self.column),
            fg="white",
            font=("Helvetica", 24)
        )
        banner.grid(
            row=0,column=0,
            sticky="ew",
            padx=10, pady=10
        )

        banner.pack(fill=tkinter.X)

# problem method
    def build_banners(self):
        self.row = 0
        self.column = 0

        self.count = 0
        for row in range (0, self.columns * 7):

            banner = tkinter.Label(
                self.mainframe,
                bg="red",
                text="Laptop booking",
                fg="white",
                font=("Helvetica", 24)
            )


            banner.grid(
                row=self.row,column=self.column,
                sticky="ew",
                padx=5, pady=5

            )

            banner.pack(fill=tkinter.BOTH, expand=True)


            print (self.count)
            self.count+=1
            self.row+=1
            if self.count % 7 == 0:
                self.count = 0
                self.row = 0
                self.column += 1


if __name__ == "__main__":
    root = tkinter.Tk()
    Body(root)
    root.mainloop()