Numerous pycharm warnings resolved

This includes:

* Better ways of checking empty lists
* Not shadowing builtin functions like filter
* Preventing invalid slash warnings by marking strings as regexps
* Removing unnecessary brackets
* Lowercase variable names
* Adding/updating parameters in docstrings
* Removing unused code (lines not chunks)
* Change in not a member tests
* Changing some methods to static
* Shorting range membership checks
* Missing parameters
* Make some exception handlers more specific
* Don't define a lambda to a variable
* A few more instance checks to help type checkers

volatility/plugins/linux/bash.py

@@ -50,7 +50,7 @@ class Bash(plugins.PluginInterface, timeliner.TimeLinerInterface):
                 continue
 
             proc_layer_name = task.add_process_layer()
-            if proc_layer_name == None:
+            if not proc_layer_name:
                 continue
 
             proc_layer = self.context.memory[proc_layer_name]
@@ -79,7 +79,7 @@ class Bash(plugins.PluginInterface, timeliner.TimeLinerInterface):
                 yield (0, (task.pid, task_name, hist.get_time_object(), hist.get_command()))
 
     def run(self):
-        filter = pslist.PsList.create_filter([self.config.get('pid', None)])
+        filt = pslist.PsList.create_filter([self.config.get('pid', None)])
 
         plugin = pslist.PsList.list_tasks
 
@@ -91,17 +91,17 @@ class Bash(plugins.PluginInterface, timeliner.TimeLinerInterface):
             self._generator(plugin(self.context,
                                    self.config['primary'],
                                    self.config['vmlinux'],
-                                   filter = filter)))
+                                   filter = filt)))
 
     def generate_timeline(self):
-        filter = pslist.PsList.create_filter([self.config.get('pid', None)])
+        filt = pslist.PsList.create_filter([self.config.get('pid', None)])
 
         plugin = pslist.PsList.list_tasks
 
         for row in self._generator(plugin(self.context,
                                           self.config['primary'],
                                           self.config['vmlinux'],
-                                          filter = filter)):
+                                          filter = filt)):
             _depth, row_data = row
             description = "{} ({}): \"{}\"".format(row_data[0], row_data[1], row_data[3])
             yield (description, timeliner.TimeLinerType.CREATED, row_data[2])

volatility/plugins/linux/elfs.py

@@ -26,7 +26,7 @@ class Elfs(plugins.PluginInterface):
     def _generator(self, tasks):
         for task in tasks:
             proc_layer_name = task.add_process_layer()
-            if proc_layer_name == None:
+            if not proc_layer_name:
                 continue
 
             proc_layer = self.context.memory[proc_layer_name]
@@ -50,7 +50,7 @@ class Elfs(plugins.PluginInterface):
                      ))
 
     def run(self):
-        filter = pslist.PsList.create_filter([self.config.get('pid', None)])
+        filt = pslist.PsList.create_filter([self.config.get('pid', None)])
 
         plugin = pslist.PsList.list_tasks
 
@@ -63,4 +63,4 @@ class Elfs(plugins.PluginInterface):
             self._generator(plugin(self.context,
                                    self.config['primary'],
                                    self.config['vmlinux'],
-                                   filter = filter)))
+                                   filter = filt)))

volatility/plugins/linux/malfind.py

@@ -27,7 +27,7 @@ class Malfind(interfaces_plugins.PluginInterface):
         """
 
         proc_layer_name = task.add_process_layer()
-        if proc_layer_name == None:
+        if not proc_layer_name:
             return
 
         proc_layer = self.context.memory[proc_layer_name]
@@ -64,7 +64,7 @@ class Malfind(interfaces_plugins.PluginInterface):
                            disasm))
 
     def run(self):
-        filter = pslist.PsList.create_filter([self.config.get('pid', None)])
+        filt = pslist.PsList.create_filter([self.config.get('pid', None)])
 
         plugin = pslist.PsList.list_tasks
 
@@ -78,4 +78,4 @@ class Malfind(interfaces_plugins.PluginInterface):
                                   self._generator(plugin(self.context,
                                                          self.config['primary'],
                                                          self.config['vmlinux'],
-                                                         filter = filter)))
+                                                         filter = filt)))

volatility/plugins/linux/pslist.py

@@ -20,13 +20,16 @@ class PsList(interfaces_plugins.PluginInterface):
 
     @classmethod
     def create_filter(cls, pid_list: List[int] = None) -> Callable[[int], bool]:
-        filter = lambda _: False
         # FIXME: mypy #4973 or #2608
         pid_list = pid_list or []
         filter_list = [x for x in pid_list if x is not None]
         if filter_list:
-            filter = lambda x: x not in filter_list
-        return filter
+            def filter_func(x):
+                return x not in filter_list
+
+            return filter_func
+        else:
+            return lambda _: False
 
     def _generator(self):
         for task in self.list_tasks(self.context,
@@ -54,7 +57,8 @@ class PsList(interfaces_plugins.PluginInterface):
         init_task = vmlinux.object(symbol_name = "init_task")
 
         for task in init_task.tasks:
-            yield task
+            if not filter(task):
+                yield task
 
     def run(self):
         return renderers.TreeGrid([("PID", int),