[property.py] Add Insert Method for Values

Insert property.value at index.
Allows also negative values for index (backwards position).

Author: fschrader1992

odml/property.py

@@ -884,6 +884,67 @@ def append(self, obj, strict=True):
 
         self._values.append(dtypes.get(new_value[0], self.dtype))
 
+    def insert(self, index, obj, strict=True):
+        """
+        Insert a single value to the list of stored values. Method will raise
+        a ValueError if the passed value cannot be converted to the current dtype.
+
+        :param obj: the additional value.
+        :param index: position of the new value
+        :param strict: a Bool that controls whether dtypes must match. Default is True.
+        """
+
+        # Ignore empty values before nasty stuff happens, but make sure
+        # 0 and False get through.
+        if obj in [None, "", [], {}]:
+            return
+
+        if not self.values:
+            self.values = obj
+            return
+
+        new_value = self._convert_value_input(obj)
+        if len(new_value) > 1:
+            raise ValueError("odml.property.insert: Use extend to add a list of values!")
+
+        new_value = self._convert_value_input(obj)
+        if len(new_value) > 1:
+            raise ValueError("odml.property.insert: Use extend to add a list of values!")
+
+        if self._dtype.endswith("-tuple"):
+            t_count = int(self._dtype.split("-")[0])
+            new_value = odml_tuple_import(t_count, new_value)
+
+        if len(new_value) > 0 and strict and \
+                dtypes.infer_dtype(new_value[0]) != self.dtype:
+
+            type_check = dtypes.infer_dtype(new_value[0])
+            if not (type_check == "string" and self.dtype in dtypes.special_dtypes) \
+                    and not self.dtype.endswith("-tuple"):
+                msg = "odml.Property.insert: passed value data type found "
+                msg += "(\"%s\") does not match expected dtype \"%s\"!" % (type_check,
+                                                                           self._dtype)
+                raise ValueError(msg)
+
+        if not self._validate_values(new_value):
+            raise ValueError("odml.Property.insert: passed value(s) cannot be converted "
+                             "to data type \'%s\'!" % self._dtype)
+
+
+        if index > len(self._values):
+            warnings.warn("odml.Property.insert: Index %i larger than length of property.values. "
+                          "Added value at end of list." % index, stacklevel=2)
+        elif index < - len(self._values) - 1:
+            warnings.warn("odml.Property.insert: Negative index %i smaller than length "
+                          "of property.values. "
+                          "Added value at beginning of list." % index, stacklevel=2)
+
+        if -len(self._values) <= index < 0:
+            index = len(self._values) + index + 1
+            print("INDEX!", index)
+
+        self._values.insert(index, dtypes.get(new_value[0], self.dtype))
+
     def pprint(self, indent=2, max_length=80, current_depth=-1):
         """
         Pretty print method to visualize Properties and Section-Property trees.