Facing a memory overflow and array index out of bound issue in YDK.

Root cause Analysis: Facing issues when  tried to compile YDK with augmented ietf_interface values. The issue is with the YDK parsing file. There were 2 issues,

         1. The YDK parser file take the base ietf_interface.py file and our augmented ietf file. It then creates a new ietf_interfaces.py file in "_aug_patch" folder with both base ietf and augmented ietf content. While parsing the comment section, the code hits a logic of end of comment (""") in the generated augmented ietf_interfaces.py file.  Ideally the logic should have ended comment parsing.  But instead the data index is decremented.

                              file:- __init__.py in ietf folder

                              if '"""' in patch_lines[idx]):                                        

                                   idx -=2

                  This was causing the code to access the same index again and again which resulted in the looping. This was causing memory issue. 

       2. In addition to the looping issue, there was array index out of bound issue.  Because of this issue the ietf_interfaces.py was not properly generated in the ietf/_aug_patch folder. IT was giving IndexError.

    Have fixed both the issues. It is purely YDK issue. The issue should be fixed in the file ydk-gen/ydkgen/printer/python/init_file_printer.py..

you could do a couple of things: 

• Raise an issue on the github issue tracker in the repo CiscoDevNet/ydk-gen
• Fork that same repository and apply your patch, and submit a pull request referencing the issue you raised.

The issue is about old Python package generated by YDK-GEN before 0.5.4 interfere with new Python package generated after 0.5.4. If you have old Python package generated and installed by YDK-GEN before 0.5.4, and facing similar issue above(error in "_aug_patch"), please uninstall them and regenerate the reinstall using YDK-GEN>=0.5.4: 

$ pip list | grep ydk-models