diff --git a/docs/src/python/figure_example.py b/docs/src/python/figure_example.py
index be3061c..ffd49b5 100644
--- a/docs/src/python/figure_example.py
+++ b/docs/src/python/figure_example.py
@@ -25,7 +25,8 @@ def main(args):
     plt.tight_layout()
 
     if args.save:
-        pu.save_fig(fig, args.save)
+        save_path = args.save if '.' in args.save else args.save + '.pdf'
+        pu.save_fig(fig, save_path)
     else:
         plt.show()
 
diff --git a/src/git_commit_stats.py b/src/git_commit_stats.py
index 6bdbb46..bcc0d1b 100644
--- a/src/git_commit_stats.py
+++ b/src/git_commit_stats.py
@@ -21,7 +21,8 @@ def load_ignore_users(file_path):
 import subprocess
 from collections import Counter
 
-def get_commits(since=None, until=None, ignore_list=[]):
+def get_commits(since=None, until=None, ignore_list=None):
+    ignore_list = ignore_list or []
     # 使用 %ae(邮箱)作为唯一键，%an(用户名)作为显示名
     cmd = ["git", "log", "--pretty=%ae|%an"]
     
@@ -31,8 +32,8 @@ def get_commits(since=None, until=None, ignore_list=[]):
     result = subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True, encoding='utf-8')
     
     if result.returncode != 0:
-        print("git log 执行失败")
-        return [], {}
+        print("git log 执行失败{result.stderr.strip()}")
+        sys.exit(1)
 
     raw_data = result.stdout.strip().split("\n")
     email_to_name = {}