Build a Prime Number Checker with Python and Tkinter

#opensource #tutorial #python #primenumberchecker

If you've ever wanted a simple GUI tool to check if a number is prime, this project is perfect for you. We'll build a Prime Number Checker using Python's tkinter library and enhance the UI with sv_ttk for theming.

The app will allow users to:

Input a number and check if it's prime.

Keep track of all numbers checked.

Toggle between light and dark mode.

Copy results to the clipboard.

Clear the history of checked numbers.

Let's dive in!

Features Overview

Interactive GUI built with Tkinter.

Dark Mode support for comfortable viewing.

Real-time results with color-coded messages:

✅ Green for prime numbers

❌ Red for non-prime numbers

History management and clipboard support.

Full Source Code

import tkinter as tk
from tkinter import ttk, messagebox, scrolledtext
import sv_ttk

# =========================
# App Setup
# =========================
root = tk.Tk()
root.title("Prime Number Checker")
root.geometry("900x600")
root.iconbitmap("")  # Add path to your icon if needed

sv_ttk.set_theme("light")  # Default theme

# =========================
# Globals
# =========================
checked_numbers = {}  # number: True/False
dark_mode_var = tk.BooleanVar(value=False)

# =========================
# Helpers
# =========================
def toggle_theme():
    if dark_mode_var.get():
        root.configure(bg="#2E2E2E")
        style.configure("TLabel", background="#2E2E2E", foreground="white")
        style.configure("TFrame", background="#2E2E2E")
        style.configure("TButton", background="#4CAF50", foreground="white")
        style.configure("TNotebook", background="#2E2E2E")
    else:
        root.configure(bg="#FFFFFF")
        style.configure("TLabel", background="#FFFFFF", foreground="black")
        style.configure("TFrame", background="#FFFFFF")
        style.configure("TButton", background="#4CAF50", foreground="white")
        style.configure("TNotebook", background="#FFFFFF")

def is_prime(n):
    if n <= 1:
        return False
    if n <= 3:
        return True
    if n % 2 == 0 or n % 3 == 0:
        return False
    i = 5
    while i * i <= n:
        if n % i == 0 or n % (i + 2) == 0:
            return False
        i += 6
    return True

def check_number():
    num_str = number_entry.get().strip()
    if not num_str.isdigit():
        messagebox.showerror("Invalid Input", "Enter a valid positive integer.")
        return
    num = int(num_str)
    prime = is_prime(num)
    checked_numbers[num] = prime
    update_results()
    number_entry.delete(0, tk.END)

def update_results():
    result_text.configure(state="normal")
    result_text.delete("1.0", tk.END)
    for num, prime in sorted(checked_numbers.items()):
        if prime:
            result_text.insert(tk.END, f"✅ {num} is a prime number.\n", "prime")
        else:
            result_text.insert(tk.END, f"❌ {num} is NOT a prime number.\n", "not_prime")
    result_text.configure(state="disabled")
    result_text.tag_configure("prime", foreground="#4CAF50")
    result_text.tag_configure("not_prime", foreground="#F44336")

def clear_history():
    checked_numbers.clear()
    update_results()

def copy_results():
    root.clipboard_clear()
    root.clipboard_append(result_text.get("1.0", tk.END))
    messagebox.showinfo("Copied", "Results copied to clipboard.")

# =========================
# Styles
# =========================
style = ttk.Style()
style.theme_use("clam")

style.configure("Action.TButton", font=("Segoe UI", 11, "bold"),
                foreground="white", background="#4CAF50", padding=8)
style.map("Action.TButton", background=[("active", "#45a049"), ("disabled", "#a5d6a7")])

style.configure("Secondary.TButton", font=("Segoe UI", 11, "bold"),
                foreground="white", background="#2196F3", padding=8)
style.map("Secondary.TButton", background=[("active", "#1976D2"), ("disabled", "#90caf9")])

# =========================
# Layout
# =========================
top_frame = ttk.Frame(root, padding=20)
top_frame.pack(fill="x")

ttk.Label(top_frame, text="Prime Number Checker", font=("Segoe UI", 20, "bold")).pack(anchor="w")
ttk.Label(top_frame, text="Enter a number and check if it is prime.", font=("Segoe UI", 11)).pack(anchor="w", pady=(0,10))

input_frame = ttk.Frame(root, padding=10)
input_frame.pack(fill="x")

ttk.Label(input_frame, text="Number:", font=("Segoe UI", 12)).pack(side="left", padx=(0,5))
number_entry = ttk.Entry(input_frame, width=20, font=("Segoe UI", 12))
number_entry.pack(side="left", padx=(0,10), ipady=4)

ttk.Button(input_frame, text="Check", command=check_number, style="Action.TButton").pack(side="left", padx=5)
ttk.Button(input_frame, text="Clear History", command=clear_history, style="Secondary.TButton").pack(side="left", padx=5)
ttk.Button(input_frame, text="Copy Results", command=copy_results, style="Secondary.TButton").pack(side="left", padx=5)

dark_frame = ttk.Frame(root, padding=10)
dark_frame.pack(fill="x")
ttk.Checkbutton(dark_frame, text="Dark Mode", variable=dark_mode_var, command=toggle_theme, style="Action.TButton").pack(anchor="w")

result_frame = ttk.LabelFrame(root, text="Results", padding=15)
result_frame.pack(fill="both", expand=True, padx=20, pady=20)

result_text = scrolledtext.ScrolledText(result_frame, state="disabled", font=("Consolas", 12))
result_text.pack(fill="both", expand=True)

# =========================
# Run App
# =========================
root.mainloop()

How It Works

Prime Check Logic: Uses a simple but efficient algorithm to determine if a number is prime.

Dynamic UI: Results are shown in a ScrolledText widget, with color-coded messages.

Dark Mode: Toggleable with a checkbox, updating all widget styles.

History Management: Keeps track of previously checked numbers and allows clearing them.

Clipboard Support: Users can copy the results for use elsewhere.

Screenshot