Python can not start Process with Process.start() on Windows. PySide signals
<p>method header:</p>

<pre><code>@engine.async
@guiLoop
def for_every_client(self):
</code></pre>

<p>connect PySide signal with method:</p>

<pre><code>self.ui.pushButton.clicked.connect(lambda: self.for_every_client(self))
</code></pre>

<p>stacktarce - <a href="http://pastebin.com/R1ZKcdPy" rel="nofollow">http://pastebin.com/R1ZKcdPy</a></p>

<p>or here:</p>

<pre><code>Traceback (most recent call last):
  File "app2.py", line 437, in &lt;lambda&gt;
    self.ui.pushButton.clicked.connect(lambda: self.for_every_client(self))
  File "c:\Python27\lib\site-packages\async_gui\engine.py", line 79, in wrapper
    gen = func(*args, **kwargs)
  File "C:\visa\visa_production\libs\guiLoop.py", line 70, in __call__
    _loop_in_the_gui(gui_element, generator, self.start_in_gui)
  File "C:\visa\visa_production\libs\guiLoop.py", line 44, in _loop_in_the_gui
    wait_time = next(generator)
  File "app2.py", line 530, in for_every_client
    p.start()
  File "c:\Python27\lib\multiprocessing\process.py", line 130, in start
    self._popen = Popen(self)
  File "c:\Python27\lib\multiprocessing\forking.py", line 277, in __init__
    dump(process_obj, to_child, HIGHEST_PROTOCOL)
  File "c:\Python27\lib\multiprocessing\forking.py", line 199, in dump
    ForkingPickler(file, protocol).dump(obj)
  File "c:\Python27\lib\pickle.py", line 224, in dump
    self.save(obj)
  File "c:\Python27\lib\pickle.py", line 331, in save
    self.save_reduce(obj=obj, *rv)
  File "c:\Python27\lib\pickle.py", line 425, in save_reduce
    save(state)
  File "c:\Python27\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "c:\Python27\lib\pickle.py", line 655, in save_dict
    self._batch_setitems(obj.iteritems())
  File "c:\Python27\lib\pickle.py", line 687, in _batch_setitems
    save(v)
  File "c:\Python27\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "c:\Python27\lib\pickle.py", line 554, in save_tuple
    save(element)
  File "c:\Python27\lib\pickle.py", line 331, in save
    self.save_reduce(obj=obj, *rv)
  File "c:\Python27\lib\pickle.py", line 425, in save_reduce
    save(state)
  File "c:\Python27\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "c:\Python27\lib\pickle.py", line 655, in save_dict
    self._batch_setitems(obj.iteritems())
  File "c:\Python27\lib\pickle.py", line 687, in _batch_setitems
    save(v)
  File "c:\Python27\lib\pickle.py", line 331, in save
    self.save_reduce(obj=obj, *rv)
  File "c:\Python27\lib\pickle.py", line 425, in save_reduce
    save(state)
  File "c:\Python27\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "c:\Python27\lib\pickle.py", line 655, in save_dict
    self._batch_setitems(obj.iteritems())
  File "c:\Python27\lib\pickle.py", line 687, in _batch_setitems
    save(v)
  File "c:\Python27\lib\pickle.py", line 331, in save
    self.save_reduce(obj=obj, *rv)
  File "c:\Python27\lib\pickle.py", line 396, in save_reduce
    save(cls)
  File "c:\Python27\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "c:\Python27\lib\pickle.py", line 754, in save_global
    (obj, module, name))
pickle.PicklingError: Can't pickle &lt;type 'PySide.QtCore.SignalInstance'&gt;: it's n
ot found as PySide.QtCore.SignalInstance
Traceback (most recent call last):
  File "&lt;string&gt;", line 1, in &lt;module&gt;
  File "c:\Python27\lib\multiprocessing\forking.py", line 381, in main
    self = load(from_parent)
  File "c:\Python27\lib\pickle.py", line 1384, in load
    return Unpickler(file).load()
  File "c:\Python27\lib\pickle.py", line 864, in load
    dispatch[key](self)
  File "c:\Python27\lib\pickle.py", line 886, in load_eof
    raise EOFError
EOFError
</code></pre>

<pre><code>class Window
    SignalProgressBar = QtCore.pyqtSignal()
    def __init__(self):
        self.SignalProgressBar.connect(lambda: self.for_every_client(self))
</code></pre>

<p>connect signal with method:</p>

<pre><code> w = Window()
 w.SignalProgressBar.emit()
</code></pre>

python windows multiprocessing pyside