get all commits sizes in a file

git_commit_sizes.py

#!/usr/bin/env python3
import csv
import subprocess
import sys

git_rev_list = subprocess.check_output(
    "git log --no-merges --pretty='%H|%an|%aI|%s' origin/master".split(" ")).decode(
    sys.stdout.encoding).rstrip().splitlines()

with open('commit_stats.csv', 'w', ) as file_handler:
    csv = csv.writer(file_handler)
    csv.writerow(["id", "author", "size", "file count", "date", "comment"])

    for git_rev in git_rev_list:
        try:
            commit_size = 0
            commit_id, author, date, comment = git_rev.strip("'").split("|", 3)
            diff_tree = subprocess.check_output(
                "git diff-tree -r -c -M -C --no-commit-id {}".format(commit_id).split(" ")).decode(sys.stdout.encoding)
            for diff in diff_tree.splitlines():
                try:
                    blob_id = diff.split(" ")[3]
                    if blob_id != "0000000000000000000000000000000000000000":
                        cat_file = subprocess.check_output("git cat-file -s {}".format(blob_id).split(" "))
                        commit_size += int(cat_file)
                except:
                    pass
            csv.writerow([commit_id, author, commit_size, len(diff_tree), date, comment])
        except ValueError:
            pass