我对PyQT5并行编程非常陌生。我想在GUI中并行运行10种方法，但我使用的Joblib异常中止。
我得到TypeError: cannot unpack non-iterable function object。我尝试使用枚举器，但仍然中止。
我的错误消息：
joblib.externals.loky.process_executor._RemoteTraceback:
"""
Traceback (most recent call last):
File "/usr/local/lib/python3.7/site-packages/joblib/externals/loky/process_executor.py", line 418, in _process_worker
r = call_item()
File "/usr/local/lib/python3.7/site-packages/joblib/externals/loky/process_executor.py", line 272, in __call__
return self.fn(*self.args, **self.kwargs)
File "/usr/local/lib/python3.7/site-packages/joblib/_parallel_backends.py", line 567, in __call__
return self.func(*args, **kwargs)
File "/usr/local/lib/python3.7/site-packages/joblib/parallel.py", line 225, in __call__
for func, args, kwargs in self.items]
File "/usr/local/lib/python3.7/site-packages/joblib/parallel.py", line 225, in <listcomp>
for func, args, kwargs in self.items]
TypeError: cannot unpack non-iterable function object
"""
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "job_parallel.py", line 73, in button_click_parallel
Parallel(n_jobs=8)(delayed(command_list[i]()) for i in range(10))
File "/usr/local/lib/python3.7/site-packages/joblib/parallel.py", line 934, in __call__
self.retrieve()
File "/usr/local/lib/python3.7/site-packages/joblib/parallel.py", line 833, in retrieve
self._output.extend(job.get(timeout=self.timeout))
File "/usr/local/lib/python3.7/site-packages/joblib/_parallel_backends.py", line 521, in wrap_future_result
return future.result(timeout=timeout)
File "/usr/local/Cellar/python/3.7.2/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/_base.py", line 432, in result
return self.__get_result()
File "/usr/local/Cellar/python/3.7.2/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/_base.py", line 384, in __get_result
raise self._exception
TypeError: cannot unpack non-iterable function object
Abort trap: 6
我的代码：
#!/usr/bin/env python3
import sys
from PyQt5 import QtCore, QtWidgets
from joblib import Parallel, delayed
import threading
class Window(QtWidgets.QMainWindow):
#uart_list = [1,2,3,4,5]
def __init__(self):
super(Window, self).__init__()
self.x_size = 800
self.y_size = 650
self.setFixedSize(self.x_size, self.y_size)
self.setWindowTitle("Test")
buttons = list()
self.button1 = QtWidgets.QPushButton("ONE", self)
self.button1.move(100,100)
buttons.append(self.button1)
self.button2 = QtWidgets.QPushButton("TWO", self)
self.button2.move(100,150)
buttons.append(self.button2)
for button in buttons:
button.clicked.connect(self.button_click_parallel)
self.show()
def run_iot_uart1(self):
print("Job 1")
def run_iot_uart2(self):
print("Job 2")
def run_iot_uart3(self):
print("Job 3")
def run_iot_uart4(self):
print("Job 4")
def run_iot_uart5(self):
print("Job 5")
def run_iot_uart6(self):
print("Job 6")
def run_iot_uart7(self):
print("Job 7")
def run_iot_uart8(self):
print("Job 8")
def run_iot_uart9(self):
print("Job 9")
def run_iot_uart10(self):
print("Job 10")
def button_click_parallel(self): # Click any button, process all UART in parallel
command_list=[self.run_iot_uart1, self.run_iot_uart2, self.run_iot_uart3,
self.run_iot_uart4, self.run_iot_uart5, self.run_iot_uart6,
self.run_iot_uart7, self.run_iot_uart8, self.run_iot_uart9,
self.run_iot_uart10]
Parallel(n_jobs=10)(delayed(command_list[i]()) for i in range(10))
sys.stdout.flush()
def run():
QtWidgets.QApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling, True)
app = QtWidgets.QApplication(sys.argv)
GUI = Window()
sys.exit(app.exec_())
run()
答案 0 :(得分：1)
问题似乎出在您的Parallel设置中。我以前从未使用过此库，但是文档提供了以下示例，其中collect是一个函数。
Parallel(n_jobs=2)(
delayed(collect)(i)
for i in range(5)
)
此处，函数被传递给delay，并且该函数的参数作为参数传递给该调用的结果。那是
delayed_function = delayed(function)
delayed_function(arg)
在示例代码中，您通过command_list[i]获取该函数，然后立即command_list[i]()对其进行调用，然后将该函数的 result （字符串）传递给{{ 1}}。
delayed我认为您正在寻找的是
Parallel(n_jobs=10)(
delayed(command_list[i]())
for i in range(10)
)
对您的代码进行更改后，我仍然收到以下错误-
Parallel(n_jobs=10)(
delayed(command_list[i])()
for i in range(10)
)
之所以会发生这种情况，是因为Parallel使用File "/usr/local/lib/python3.6/site-packages/joblib/parallel.py", line 183, in
delayed
pickle.dumps(function)
TypeError: can't pickle Window objects
（Python序列化格式）将函数和参数发送给执行程序。不幸的是，看起来pickle（可能还有其他Qt对象？）不可腌制。由于您的窗口方法需要访问QWindow，因此需要对其进行腌制。
解决方案是将这些方法a）移至可腌制的类，b）移至函数。下面是第二步。
self运行此命令并按“ ONE”按钮，将得到以下输出。
#!/usr/bin/env python3
import sys
from PyQt5 import QtCore, QtWidgets
from joblib import Parallel, delayed
import threading
def run_iot_uart1():
print("Job 1")
def run_iot_uart2():
print("Job 2")
def run_iot_uart3():
print("Job 3")
def run_iot_uart4():
print("Job 4")
def run_iot_uart5():
print("Job 5")
def run_iot_uart6():
print("Job 6")
def run_iot_uart7():
print("Job 7")
def run_iot_uart8():
print("Job 8")
def run_iot_uart9():
print("Job 9")
def run_iot_uart10():
print("Job 10")
class Window(QtWidgets.QMainWindow):
#uart_list = [1,2,3,4,5]
def __init__(self):
super(Window, self).__init__()
self.x_size = 800
self.y_size = 650
self.setFixedSize(self.x_size, self.y_size)
self.setWindowTitle("Test")
buttons = list()
self.button1 = QtWidgets.QPushButton("ONE", self)
self.button1.move(100,100)
buttons.append(self.button1)
self.button2 = QtWidgets.QPushButton("TWO", self)
self.button2.move(100,150)
buttons.append(self.button2)
for button in buttons:
button.clicked.connect(self.button_click_parallel)
self.show()
def button_click_parallel(self): # Click any button, process all UART in parallel
command_list=[run_iot_uart1, run_iot_uart2, run_iot_uart3,
run_iot_uart4, run_iot_uart5, run_iot_uart6,
run_iot_uart7, run_iot_uart8, run_iot_uart9,
run_iot_uart10]
Parallel(n_jobs=10)(delayed(command_list[i])() for i in range(10))
sys.stdout.flush()
def run():
QtWidgets.QApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling, True)
app = QtWidgets.QApplication(sys.argv)
GUI = Window()
sys.exit(app.exec_())
run()