我有以下問題：
我正在嘗試使用 concurrent.futures.ProcessPoolExecutor() 或任何類似的東西，并在 tkinter 小部件上顯示每個行程的進度。
有這個答案： Python Tkinter multiprocessing progress但我不能讓它作業。
我的代碼的以下簡化版本似乎僅在使用我不想要的 ThreadPoolExecutor() 時才有效。
在此先感謝您的幫助！
import concurrent.futures
import tkinter
import tkinter.ttk
import multiprocessing
import random
import time
class App:
def __init__(self, root):
self.root = root
self.processes = 5
self.percentage = []
self.changing_labels = []
self.queues = []
self.values = []
for i in range(self.processes):
temp_percentage = tkinter.StringVar()
temp_percentage.set("0 %")
self.percentage.append(temp_percentage)
temp_changing_label = tkinter.Label(self.root, textvariable=temp_percentage)
temp_changing_label.pack()
self.changing_labels.append(temp_changing_label)
self.queues.append(multiprocessing.Queue())
# Just same values that I want to do calculations on
temp_value = []
for ii in range(12):
temp_value.append(random.randrange(10))
self.values.append(temp_value.copy())
self.start_processing()
def start_processing(self):
def save_values(my_values): # Save my new calculated values on the same file or different file
with open(f"example.txt", "a") as file:
for v in my_values:
file.write(str(v))
file.write(" ")
file.write("\n")
def work(my_values, my_queue): # Here I do all my work
# Some values to calculate my progress so that I can update my Labels
my_progress = 0
step = 100 / len(my_values)
# Do some work on the values
updated_values = []
for v in my_values:
time.sleep(0.5)
updated_values.append(v 1)
my_progress = step
my_queue.put(my_progress) # Add current progress to queue
save_values(updated_values) # Save it before exiting
# This Part does no work with ProcessPoolExecutor, with ThreadPoolExecutor it works fine
with concurrent.futures.ProcessPoolExecutor() as executor:
results = [executor.submit(work, self.values[i], self.queues[i])
for i in range(self.processes)]
# Run in a loop and update Labels or exit when done
while True:
results_done = [result.done() for result in results]
if False in results_done:
for i in range(self.processes):
if results_done[i] is False:
if not self.queues[i].empty():
temp_queue = self.queues[i].get()
self.percentage[i].set(f"{temp_queue:.2f} %")
else:
self.percentage[i].set("100 %")
self.root.update()
else:
break
# Close window at the very end
self.root.destroy()
def main(): # Please do not change my main unless it is essential
root = tkinter.Tk()
my_app = App(root)
root.mainloop()
if __name__ == "__main__":
main()
uj5u.com熱心網友回復：
該問題是由在新行程中引發的例外引起的。要查看此例外，您可以呼叫Future.result引發例外的函式，例如
print([result.result() for result in results])
這給出了錯誤AttributeError: Can't pickle local object 'App.start_processing.<locals>.work'，所以問題是work在另一個函式中定義的。
將work和save_values函式移出start_processing方法后，錯誤變為RuntimeError: Queue objects should only be shared between processes through inheritance。這可以通過使用 amultiprocessing.Manager創建佇列來解決：
class App:
def __init__(self, root):
...
with multiprocessing.Manager() as manager:
for i in range(self.processes):
...
self.queues.append(manager.Queue())
...
self.start_processing()
該print([result.result() for result in results])除錯線現在可以洗掉。完整代碼如下：
import concurrent.futures
import tkinter
import tkinter.ttk
import multiprocessing
import random
import time
class App:
def __init__(self, root):
self.root = root
self.processes = 5
self.percentage = []
self.changing_labels = []
self.queues = []
self.values = []
with multiprocessing.Manager() as manager:
for i in range(self.processes):
temp_percentage = tkinter.StringVar()
temp_percentage.set("0 %")
self.percentage.append(temp_percentage)
temp_changing_label = tkinter.Label(self.root, textvariable=temp_percentage)
temp_changing_label.pack()
self.changing_labels.append(temp_changing_label)
self.queues.append(manager.Queue())
# Just same values that I want to do calculations on
temp_value = []
for ii in range(12):
temp_value.append(random.randrange(10))
self.values.append(temp_value.copy())
self.start_processing()
@staticmethod
def save_values(my_values): # Save my new calculated values on the same file or different file
with open(f"example.txt", "a") as file:
for v in my_values:
file.write(str(v))
file.write(" ")
file.write("\n")
@classmethod
def work(cls, my_values, my_queue): # Here I do all my work
# Some values to calculate my progress so that I can update my Labels
my_progress = 0
step = 100 / len(my_values)
# Do some work on the values
updated_values = []
for v in my_values:
time.sleep(0.5)
updated_values.append(v 1)
my_progress = step
my_queue.put(my_progress) # Add current progress to queue
cls.save_values(updated_values) # Save it before exiting
def start_processing(self):
# This Part does no work with ProcessPoolExecutor, with ThreadPoolExecutor it works fine
with concurrent.futures.ProcessPoolExecutor() as executor:
results = [executor.submit(self.work, self.values[i], self.queues[i])
for i in range(self.processes)]
# Run in a loop and update Labels or exit when done
while True:
results_done = [result.done() for result in results]
if False in results_done:
for i in range(self.processes):
if results_done[i] is False:
if not self.queues[i].empty():
temp_queue = self.queues[i].get()
self.percentage[i].set(f"{temp_queue:.2f} %")
else:
self.percentage[i].set("100 %")
self.root.update()
else:
break
# Close window at the very end
self.root.destroy()
def main(): # Please do not change my main unless it is essential
root = tkinter.Tk()
my_app = App(root)
root.mainloop()
if __name__ == "__main__":
main()
PS：我會推薦not all(results_done)而不是False in results_done，not results_done[i]而不是results_done[i] is False。
轉載請註明出處，本文鏈接：https://www.uj5u.com/net/335952.html
上一篇：“ValueError:toomanyvaluestounpack(expected2)”不應該在這里發生
下一篇：在Tkinter中回圈放置影像