To convert a gitlog to an array of commits, one can use the git_log_to_array.py script. It requires a local copy of the git repository that is aimed to be analyzed. As an example one can use the Jenkins repository.
First clone the repository to a location of your own choice.
git clone https://github.com/jenkinsci/jenkins
Then decide from which commit the script should produce an array from. In this example the following commit was chosen, 02d6908ada70fcf8012833ddef628bc09c6f8389. Then run the script using:
python git_log_to_array.py --repo-path <path_to_cloned_repo>/jenkins --from-commit 02d6908ada70fcf8012833ddef628bc09c6f8389
The results from the script will be assembled in the file gitlog.json. An example of this run can be found in data/gitlog.json.