fix: migrated (PR 4146): Set _post as a property so it's initialized when needed (#4147)

* Set _post as a property so it is not called anymore when it's not initialised yet

* chore: adding changelog file 4147.miscellaneous.md [dependabot-skip]

* chore: adding changelog file 4147.miscellaneous.md [dependabot-skip]

* refactor: improve post-processing object initialization in _MapdlCore

---------

Co-authored-by: valallansys <valentin.allard@ansys.com>
Co-authored-by: German <28149841+germa89@users.noreply.github.com>

Author: 3 people

doc/changelog.d/4147.miscellaneous.md

@@ -0,0 +1 @@
+Fix: migrated (PR 4146): Set _post as a property so it's initialized when needed

src/ansys/mapdl/core/mapdl_core.py

@@ -375,7 +375,8 @@ def __init__(
         if log_apdl:
             self.open_apdl_log(log_apdl, mode="w")
 
-        self._post = PostProcessing(self)
+        # Empty object that will store the `PostProcessing` object
+        self._post_object = None
 
         # Wrapping listing functions for "to_array" methods
         self._wrap_listing_functions()
@@ -963,7 +964,11 @@ def post_processing(self) -> "PostProcessing":
             raise MapdlRuntimeError(
                 "MAPDL exited.\n\nCan only postprocess a live " "MAPDL instance."
             )
-        return self._post
+
+        if self._post_object is None:
+            self._post_object = PostProcessing(self)
+
+        return self._post_object
 
     @property
     def print_com(self):