Rows & Columns generator

import tkinter as tk

def generate_pattern(rows, cols):
    pattern = ""
    for i in range(rows):
        for j in range(cols):
            if (i + j) % 2 == 0:
                pattern += "*"
            else:
                pattern += "-"
        pattern += "\n"
    return pattern

def show_pattern():
    num_rows = int(rows_entry.get())
    num_cols = int(cols_entry.get())

    pattern = generate_pattern(num_rows, num_cols)
    pattern_text.configure(state='normal')
    pattern_text.delete("1.0", tk.END)
    pattern_text.insert(tk.END, pattern)
    pattern_text.configure(state='disabled')

def toggle_dark_mode():
    dark_mode.set(not dark_mode.get())
    if dark_mode.get():
        pattern_frame.config(bg="black")
        pattern_text.config(bg="black", fg="white", insertbackground="white")
        dark_mode_button.config(text="\u263E")  # Moon symbol
    else:
        pattern_frame.config(bg="white")
        pattern_text.config(bg="white", fg="black", insertbackground="black")
        dark_mode_button.config(text="\u2600")  # Sun symbol

window = tk.Tk()
window.title("Pattern Generator")

dark_mode = tk.BooleanVar()
dark_mode_button = tk.Button(window, text="\u2600", font=("Arial", 12), command=toggle_dark_mode)
dark_mode_button.pack()

rows_label = tk.Label(window, text="Number of Rows:")
rows_label.pack()

rows_entry = tk.Entry(window)
rows_entry.pack()

cols_label = tk.Label(window, text="Number of Columns:")
cols_label.pack()

cols_entry = tk.Entry(window)
cols_entry.pack()

generate_button = tk.Button(window, text="Generate Pattern", command=show_pattern)
generate_button.pack()

pattern_frame = tk.Frame(window, bg="white")
pattern_frame.pack()

pattern_text = tk.Text(pattern_frame, state='disabled')
pattern_text.pack()

window.mainloop()