Switched to using "not" instead of ! modifier.

printcore.py

@@ -222,7 +222,7 @@ class printcore():
     def pause(self):
         """Pauses the print, saving the current position.
         """
-        if !self.printing: return False
+        if not self.printing: return False
         self.paused = True
         self.printing = False
         self.print_thread.join()
@@ -231,7 +231,7 @@ class printcore():
     def resume(self):
         """Resumes a paused print.
         """
-        if !self.paused: return False
+        if not self.paused: return False
         self.paused = False
         self.printing = True
         self.print_thread = Thread(target = self._print)