Alright, let's break down why your Tkinter app runs smoothly on Ubuntu but hits snags on Windows when spawning that calculation script with a progress bar window. Windows handles subprocesses, threading, and GUI updates differently than Linux—so those differences are almost certainly the root cause. Here are the most likely culprits and actionable fixes:

1. Subprocess Spawning Quirks on Windows #

Linux and Windows resolve Python executables and script paths differently, which can break your script launch:

• Always use the full path to your Python executable (instead of just python) to avoid version conflicts. You can grab this dynamically with sys.executable.
• Skip shell=True unless you absolutely need it—it’s less secure and causes path resolution headaches. Pass the Python path and script path as a list to subprocess.Popen.
  Example:

  import subprocess
  import sys
  from pathlib import Path
  
  # Dynamically get paths (cross-platform friendly)
  python_exe = sys.executable
  calc_script = str(Path(__file__).parent / "Calculations.py")
  
  # Launch the script safely
  process = subprocess.Popen(
      [python_exe, calc_script],
      stdout=subprocess.PIPE,
      stderr=subprocess.PIPE,
      text=True
  )
  

2. Thread Safety with Tkinter #

Tkinter isn’t thread-safe, and Windows enforces this rule far more strictly than Linux. If you’re updating the progress bar directly from a background thread monitoring your queue, that’s a guaranteed freeze:

• Use root.after() to schedule all GUI updates from the main thread. Never modify Tkinter widgets from a background thread.
  Example of safe queue monitoring:

  def check_progress_queue():
      while not progress_queue.empty():
          current_progress = progress_queue.get()
          # Update progress bar (safe—this runs in the main Tkinter thread)
          progress_bar["value"] = current_progress
      # Schedule next check in 100ms
      root.after(100, check_progress_queue)
  
  # Start monitoring when you launch the calculation
  root.after(0, check_progress_queue)
  

3. Multiprocessing Queue Behavior on Windows #

Windows uses a "spawn" model for multiprocessing (instead of Linux’s "fork"), which can break queue-based progress updates:

• If you’re using multiprocessing.Queue, make sure all objects passed through it are picklable (most basic types are, but custom classes might need tweaks).
• Alternatively, switch to piping progress updates via stdout: have Calculations.py print progress percentages to stdout, then read those lines in your GUI’s monitoring thread. This is often more reliable cross-platform.

4. Blocking the Main GUI Thread #

If your progress bar window freezes entirely, chances are your main Tkinter thread is blocked waiting for the calculation script to finish:

• Always run the calculation launch and monitoring logic in a background thread. The main thread needs to stay free to handle Tkinter events (like rendering the progress bar).
  Example of launching the calculation in a thread:

  import threading
  import tkinter as tk
  
  def run_calculation_task():
      # Code to spawn subprocess, monitor progress, and feed queue goes here
      pass
  
  # Attach to your button click
  root = tk.Tk()
  run_btn = tk.Button(
      root,
      text="Start Calculation",
      command=lambda: threading.Thread(target=run_calculation_task, daemon=True).start()
  )
  run_btn.pack()
  root.mainloop()
  

5. Cross-Platform Path Handling #

Windows uses backslashes for file paths, while Ubuntu uses forward slashes. Hardcoded paths or incorrect path formatting will break your script on Windows:

• Use pathlib or os.path to handle paths dynamically—never hardcode slashes.
  Example with pathlib:

  from pathlib import Path
  
  # Get the folder where your GUI script lives
  app_folder = Path(__file__).parent
  # Build path to Calculations.py
  calc_script_path = app_folder / "Calculations.py"
  

If you can share a minimal snippet of your code (especially the part where you launch the calculation and update the progress bar), I can help narrow this down even further!

内容的提问来源于stack exchange，提问作者tzoukritzou