small optimization

.gitignore

@@ -2,3 +2,4 @@ sample.log
 __pycache__/*
 *.pyc
 *.cached_ips.pkl
+*.gz*

analyze.py

@@ -81,9 +81,10 @@ def latlon_distance(p1, p2) -> float:
 
     return c * earth_radius_km
 
-def analyze_server(server: Path, serverip: str) -> None:
+def analyze_server(server: Path) -> None:
     if not server.is_dir():
         return
+    serverip = get_server_ip(server.name)
 
     result = ''
 
@@ -135,16 +136,14 @@ def main(args: list) -> int:
     outfile = 'analysis.csv'
     start_dir = Path('.').resolve()
 
-    f = open(outfile, 'w')
-    for logdir in args[1:]:
-        chdir(logdir)
-        serverdir = Path('.')
-        for subdir in serverdir.iterdir():
-            serverip = get_server_ip(subdir.name)
-            csv_lines = analyze_server(subdir, serverip)
-        chdir(start_dir)
-        f.write(csv_lines)
-    f.close()
+    with open(outfile, 'w') as f:
+        for logdir in args[1:]:
+            chdir(logdir)
+            serverdir = Path('.')
+            for subdir in serverdir.iterdir():
+                csv_lines = analyze_server(subdir)
+                f.write(csv_lines)
+            chdir(start_dir)
 
     return 0