Build a High-Performance Fibonacci Generator with Python and Tkinter

#tutorial #opensource #fibotool #python

In this tutorial, we’ll create FiboTool, a GUI application that generates Fibonacci sequences efficiently, displays them in real-time, and allows copying or exporting the results. We’ll use Python, Tkinter, and threading to keep the interface responsive.

Features

Generate large Fibonacci sequences (up to 100,000 terms)

Live streamed output to the text box

Copy results to clipboard

Export results as a .txt file

Responsive UI with a progress bar

Requirements

Python 3.10+

tkinter (built-in with Python)

sv_ttk for modern light/dark themes

Install sv_ttk:

pip install sv_ttk

Full Source Code

import sys
import os
import threading
import tkinter as tk
from tkinter import ttk, messagebox, filedialog
import sv_ttk

# =========================
# Helpers
# =========================
def resource_path(file_name):
    base_path = getattr(sys, "_MEIPASS", os.path.dirname(os.path.abspath(__file__)))
    return os.path.join(base_path, file_name)

# =========================
# App Setup
# =========================
root = tk.Tk()
root.title("FiboTool")
root.geometry("980x620")
root.minsize(900, 550)

sv_ttk.set_theme("light")

# =========================
# Globals
# =========================
count_var = tk.IntVar(value=100)
status_var = tk.StringVar(value="Ready")

# =========================
# Status
# =========================
def set_status(msg):
    status_var.set(msg)
    root.update_idletasks()

# =========================
# Fibonacci Logic (STREAMED)
# =========================
def generate_fibonacci():
    try:
        n = count_var.get()
        if n <= 0 or n > 100000:
            raise ValueError
    except Exception:
        messagebox.showerror("Invalid Input", "Enter a number between 1 and 100,000.")
        return

    output.delete("1.0", tk.END)
    progress["value"] = 0
    progress["maximum"] = n
    set_status("Generating sequence...")

    def task():
        a, b = 0, 1
        chunk = []

        for i in range(n):
            chunk.append(str(a))
            a, b = b, a + b

            if i % 100 == 0:
                text = ", ".join(chunk) + ", "
                root.after(0, output.insert, tk.END, text)
                root.after(0, progress.step, 100)
                chunk.clear()

        if chunk:
            root.after(0, output.insert, tk.END, ", ".join(chunk))

        root.after(0, lambda: progress.config(value=n))
        root.after(0, set_status, f"Generated {n} terms")

    threading.Thread(target=task, daemon=True).start()

def copy_result():
    root.clipboard_clear()
    root.clipboard_append(output.get("1.0", tk.END))
    set_status("Copied to clipboard")

def export_txt():
    file_path = filedialog.asksaveasfilename(
        defaultextension=".txt",
        filetypes=[("Text Files", "*.txt")]
    )
    if not file_path:
        return

    with open(file_path, "w", encoding="utf-8") as f:
        f.write(output.get("1.0", tk.END))

    set_status(f"Saved to {os.path.basename(file_path)}")

# =========================
# Styles
# =========================
style = ttk.Style()
style.configure("Title.TLabel", font=("Segoe UI", 24, "bold"))
style.configure("Subtitle.TLabel", font=("Segoe UI", 11))
style.configure("Action.TButton", font=("Segoe UI", 11, "bold"), padding=10)

# =========================
# Layout (GRID-BASED)
# =========================
root.columnconfigure(0, weight=1)
root.rowconfigure(1, weight=1)

# ----- Header -----
header = ttk.Frame(root, padding=(24, 16))
header.grid(row=0, column=0, sticky="ew")

header.columnconfigure(1, weight=1)

ttk.Label(header, text="FiboTool", style="Title.TLabel").grid(row=0, column=0, sticky="w")
ttk.Label(
    header,
    text="High-performance Fibonacci sequence generator",
    style="Subtitle.TLabel"
).grid(row=1, column=0, sticky="w", pady=(2, 0))

controls = ttk.Frame(header)
controls.grid(row=0, column=1, rowspan=2, sticky="e")

ttk.Label(controls, text="Terms").grid(row=0, column=0, padx=6)
ttk.Entry(controls, textvariable=count_var, width=10).grid(row=0, column=1)

# ----- Main Content -----
main = ttk.Frame(root, padding=(24, 0, 24, 16))
main.grid(row=1, column=0, sticky="nsew")
main.columnconfigure(0, weight=1)
main.rowconfigure(0, weight=1)

output_card = ttk.LabelFrame(main, text="Output", padding=10)
output_card.grid(row=0, column=0, sticky="nsew")
output_card.columnconfigure(0, weight=1)
output_card.rowconfigure(0, weight=1)

scroll = ttk.Scrollbar(output_card)
scroll.grid(row=0, column=1, sticky="ns")

output = tk.Text(
    output_card,
    wrap="word",
    font=("Consolas", 10),
    yscrollcommand=scroll.set
)
output.grid(row=0, column=0, sticky="nsew")
scroll.config(command=output.yview)

# ----- Actions -----
actions = ttk.Frame(main)
actions.grid(row=1, column=0, pady=12, sticky="ew")

ttk.Button(
    actions,
    text="Generate",
    command=generate_fibonacci,
    style="Action.TButton"
).pack(side="left")

ttk.Button(actions, text="Copy", command=copy_result).pack(side="left", padx=6)
ttk.Button(actions, text="Export TXT", command=export_txt).pack(side="left")

progress = ttk.Progressbar(actions)
progress.pack(side="right", fill="x", expand=True, padx=(12, 0))

# ----- Status Bar -----
status = ttk.Label(root, textvariable=status_var, anchor="w", padding=6)
status.grid(row=2, column=0, sticky="ew")

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

How It Works

Threading for Responsiveness: The Fibonacci calculation runs in a separate thread so the UI doesn’t freeze.

Chunked Output: Instead of inserting each number individually, we batch them for performance.

Progress Bar: Shows progress dynamically as the sequence generates.

Copy & Export: Convenient ways to save or share results.

Demo Screenshot