Print out the number of commits by year in a repo

git-stats.py

#! /usr/bin/env python3

"""
NAME
    git-stats

DESCRIPTION
    Display the number of commits in a repo by year as a number and histogram.
    
NOTE
    I may tweak it over time to add other stats which is why it's not called something like git-commit-stats.
"""

import sys
import subprocess

from collections import defaultdict
from datetime import datetime


data = subprocess.check_output(["git", "-C", sys.argv[1] if len(sys.argv) > 1 else ".", "log", "--all", "--format=format:%ct"])
dates: list[datetime] = map(datetime.fromtimestamp, map(int, data.splitlines()))

stats = defaultdict(int)
for date in sorted(dates):
    stats[date.year] += 1

print("year", "commits", "histogram")
for period, count in stats.items():
    print(period, f"{count:7d}", "#" * (count // 100))