pymodulepackage (schueltke): fix for tool_level access

Problem:

• when tool_level in aircraft exchange file is accessed by a module but is not existing, the pymodulepackage throws an error as it can be seen and discussed in weight_and_balance_analysis: aircraft-design!31 (comment 2743760) Solution:
• implement a handling procedure how to continue, when tool_level access failed and set tool_level to 0 in that case

Test:

• test previous version using weight_and_balance_analysis with an aircraft exchange file in a first loop, when tool_level is not yet written in the node masses_cg_inertia and compare it with an execution when the attribute was already written by weight_and_balance_analysis
• test the same procedure with the fix from this MR

pymodulepackage/src/datapreprocessingmodule.py

@@ -580,7 +580,11 @@ def read_values_from_xml_file(input_dict, root_of_xml_file, runtime_output):
                 elif tmp_dict[tmp_key][1] == 'tool_level':
                     tmp_parameter = root_of_xml_file.find(tmp_dict[tmp_key][0])
                     if tmp_parameter is not None:
-                        return_dict[tmp_key] += [tmp_parameter.attrib['tool_level']]
+                        if 'tool_level' not in tmp_parameter.attrib:
+                            current_tool_level = 0
+                        else:
+                            current_tool_level = tmp_parameter.attrib['tool_level']
+                        return_dict[tmp_key] += [current_tool_level]
                 else:
                     # Check existence of every parameter in 'parameter_list' and append text if given and 'None' if not.
                     for parameter in parameter_list: