Google Summer of Code 2019 - Final report
Project: scancode-toolkit to Python 3
Owner: Abhishek Kumar
Mentor: Philippe Ombredanne
Problem: Since Python 2.7 will retire in few months and will not be maintained any longer.
Solution: Scancode needs to be ported to python 3 and all test suites must pass on both version of Python. The main difference that makes Python 3 better than Python 2.x is that the support for unicode is greatly improved in Python 3. This will also be useful for scancode as scancode has users in more than 100 languages and it’s easy to translate strings from unicode to other languages.
Objective: To make scancode-toolkit installable on on Python 3.6 and higher, as presently it installs with Python 2.7 only.
It was started in development mode(editable mode) and then it was moved to work in virtual environments.
I have worked module by module according to the order of hierarchy of modules. For example :All module is dependent on commoncode, so it must be ported first. In this way we have created the Porting order:
scancode basics (some tests are integration tests and will have to wait to be ported)
formattedcode, starting with JSON (some tests are integration tests and will have to wait to be ported)
packagedcode (depends on licensecode)
fixup the remaining bits and tests
After porting each module, I have marked these modules as ported
scanpy3 with help of
conffest plugin (created by @pombredanne). Conffest
plugin is heart of this project. Without this, it was very difficult to do. Dependencies was fixed
at the time of porting the module where it was used.
Challenging part of Project
It is very difficult to deal with paths on different operating systems.The issue is around
macOS/Windows/Linux. The first two OS handle unicode paths comfortably on Python 2 and 3 but not
completely on macOS Mojave because its filesystem encoding is APFS. Linux paths are bytes and
os.listdir is broken on Python 2. As a result you can only sanely handle Linux paths as bytes
on Python 2. But on Python 3 path seems to be corrected as
unicode on Linux.
For more details visit here :
We came with various Solution:
To use pathlib which generally handle paths correctly across platforms. And for backports we use pathlib 2. But this solution also fails because pathlib 2 does not work as expected wrt unicode vs bytes. And os.listdir also doesn’t work properly.
To use path.py which handles the paths across all the platforms even on macOS Mojave .
byteson linux and python 3 and
We choose the third solution because it is most fundamental and simple and easy to use.
Project was tracked in this ticket nexB/scancode-toolkit#295
Project link : Port Scancode to Python 3
My contribution : List of Commits
Note : Please give your feedback here
Now we have liftoff on Python 3 . We are able to run basic scans without errors on develop branch.
You check it by running
scancode -clipeu samples/ --json-pp - -n4 .
At last I would like to thanks my Mentor @pombredanne aka Philippe Ombredanne . He has helped lot in completing this project. He is very supportive and responsive. I have learned a lot from him. By his encouragement and motivation, I am very improving day by day, building and developing my skills. I have completed all the tasks that were in the scope of this GSoC project.