Use signals emitted by Spyder to update plugin

Use signals to update the widget's copy of the Spyder PYTHONPATH

spyder_line_profiler/lineprofiler.py

@@ -88,7 +88,16 @@ def __init__(self, parent=None):
 
         # Initialize plugin
         self.initialize_plugin()
-
+
+    def update_pythonpath(self):
+        """
+        Update the PYTHONPATH used when running the line_profiler.
+        This function is called whenever the Python path set in Spyder changes.
+        It synchronizes the PYTHONPATH in the line_profiler widget with the
+        PYTHONPATH in Spyder.
+        """
+        self.widget.spyder_pythonpath = self.main.get_spyder_pythonpath()
+
     # --- SpyderPluginWidget API ----------------------------------------------
     def get_plugin_title(self):
         """Return widget title."""
@@ -117,6 +126,10 @@ def on_first_registration(self):
 
     def register_plugin(self):
         """Register plugin in Spyder's main window."""
+        # Spyder PYTHONPATH
+        self.update_pythonpath()
+        self.main.sig_pythonpath_changed.connect(self.update_pythonpath)
+
         self.edit_goto.connect(self.main.editor.load)
         self.widget.redirect_stdio.connect(self.main.redirect_internalshell_stdio)
         self.main.add_dockwidget(self)

spyder_line_profiler/widgets/lineprofiler.py

@@ -87,15 +87,10 @@ class LineProfilerWidget(QWidget):
 
     def __init__(self, parent):
         QWidget.__init__(self, parent)
-        self.main = parent
-        if self.main is None:
-            # Fail gracefully if not passed the spyder MainWindow
-            self.main = type('main', (object,), {})
-            self.main.get_spyder_pythonpath = (lambda self: None)
-            self.main = self.main()
         # Need running QApplication before importing runconfig
         from spyder.plugins import runconfig
         self.runconfig = runconfig
+        self.spyder_pythonpath = None
 
         self.setWindowTitle("Line profiler")
 
@@ -225,7 +220,7 @@ def analyze(self, filename=None, wdir=None, args=None, pythonpath=None,
             if wdir is None:
                 wdir = osp.dirname(filename)
             if pythonpath is None:
-                pythonpath = self.main.get_spyder_pythonpath()
+                pythonpath = self.spyder_pythonpath
             self.start(wdir, args, pythonpath)
 
     def select_file(self):