stats: read git log from stdin

contribution-stats.py

 #! /usr/bin/env python
 from pygit2 import Repository, Tag
 from pygit2 import GIT_SORT_TOPOLOGICAL
+import sys
+import csv
 import re
 
 details=True
@@ -65,16 +67,8 @@ def print_commits(dict):
 
 if __name__ == "__main__":
     repo = Repository(GIT_TREE)
-
-    first_commit = repo.revparse_single('v3.12')
-    if isinstance(first_commit, Tag):
-        first_commit = first_commit.get_object()
-
-    last_commit = repo.revparse_single('HEAD')
-    if isinstance(last_commit, Tag):
-        last_commit = last_commit.get_object()
-
-    for commit in repo.walk(last_commit.id, GIT_SORT_TOPOLOGICAL):
+    for line in csv.reader(sys.stdin, delimiter=','):
+        commit = repo.get(line[0])
         if EMAIL_PATTERN in commit.author.email:
             add_contributor(contributors, commit.author.email, commit.author.name)
             add_commit(authored, commit.author.email, commit)
@@ -95,9 +89,6 @@ if __name__ == "__main__":
             for m in match:
                 add_contributor(contributors, m[1], m[0])
                 add_commit(tag[1], m[1], commit)
-
-        if commit.id == first_commit.id:
-            break
     
     print("# Authored (%d)\n" % total_commits(authored))
     print_commits(authored)