Prepare for new dump path handling

src/oemof/network/energy_system.py

@@ -216,40 +216,82 @@ def flows(self):
             for target in source.outputs
         }
 
-    def dump(self, dpath=None, filename=None):
+    # Begin: to be removed in a future version
+    @staticmethod
+    def _deprecated_path_handling(dpath, filename, consider_dpath):
+        if consider_dpath:
+            if dpath is None:
+                bpath = os.path.join(os.path.expanduser("~"), ".oemof")
+                if not os.path.isdir(bpath):
+                    os.mkdir(bpath)
+                dpath = os.path.join(bpath, "dumps")
+                if not os.path.isdir(dpath):
+                    os.mkdir(dpath)
+
+                warnings.warn(
+                    "Default directory for oemof dumps will change"
+                    + "from ~/.oemof/dumps/ to ./ in a future version."
+                    + " Set 'consider_dpath' to False to already use"
+                    + " the new default.",
+                    FutureWarning,
+                )
+            else:
+                warnings.warn(
+                    "Parameter 'dpath' will be removed in a future"
+                    + " version. You can give the directory as part"
+                    + " of the filename and set 'consider_dpath' to"
+                    + " False to suppress this waring.",
+                    FutureWarning,
+                )
+            if filename is None:
+                filename = "es_dump.oemof"
+
+            filename = os.path.join(dpath, filename)
+        else:
+            if dpath is not None:
+                if filename is None:
+                    # Interpret dpath as intended to be filename,
+                    # as it might be given as positional argument.
+                    filename = dpath
+                else:
+                    raise ValueError(
+                        "You set filename and dpath but told that"
+                        + " dpath should be ignored."
+                    )
+
+        return filename
+        # End: to be removed in a future version
+
+    def dump(self, dpath=None, filename=None, consider_dpath=True):
         r"""Dump an EnergySystem instance."""
-        if dpath is None:
-            bpath = os.path.join(os.path.expanduser("~"), ".oemof")
-            if not os.path.isdir(bpath):
-                os.mkdir(bpath)
-            dpath = os.path.join(bpath, "dumps")
-            if not os.path.isdir(dpath):
-                os.mkdir(dpath)
-
-        if filename is None:
-            filename = "es_dump.oemof"
+        filename = self._deprecated_path_handling(
+            dpath, filename, consider_dpath
+        )
 
-        pickle.dump(self.__dict__, open(os.path.join(dpath, filename), "wb"))
+        pickle.dump(self.__dict__, open(filename, "wb"))
 
-        msg = "Attributes dumped to: {0}".format(os.path.join(dpath, filename))
+        msg = "Attributes dumped to: {0}".format(filename)
         logging.debug(msg)
         return msg
 
-    def restore(self, dpath=None, filename=None):
+    def restore(
+        self,
+        dpath=None,  # to be removed in a future version
+        filename=None,
+        consider_dpath=True,  # to be removed in a future version
+    ):
         r"""Restore an EnergySystem instance."""
         logging.info(
             "Restoring attributes will overwrite existing attributes."
         )
-        if dpath is None:
-            dpath = os.path.join(os.path.expanduser("~"), ".oemof", "dumps")
-
-        if filename is None:
-            filename = "es_dump.oemof"
+        # Start: to be removed in a future version
+        filename = self._deprecated_path_handling(
+            dpath, filename, consider_dpath
+        )
+        # End: to be removed in a future version
 
-        self.__dict__ = pickle.load(open(os.path.join(dpath, filename), "rb"))
+        self.__dict__ = pickle.load(open(filename, "rb"))
 
-        msg = "Attributes restored from: {0}".format(
-            os.path.join(dpath, filename)
-        )
+        msg = "Attributes restored from: {0}".format(os.path.join(filename))
         logging.debug(msg)
         return msg