use open context managers in more places

Use open() as a context manager to simplify the close logic and make
the code easier to read & understand.  This is also more Pythonic.

Change-Id: I579d03cca86f99b2c6c6a1f557f6e5704e2515a7
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/244734
Reviewed-by: David Pursehouse <dpursehouse@collab.net>
Tested-by: Mike Frysinger <vapier@google.com>

2 files changed, 8 insertions, 24 deletions

diff --git a/subcmds/manifest.py b/subcmds/manifest.py
index 768f072e..9c1b3f0c 100644
--- a/subcmds/manifest.py
+++ b/subcmds/manifest.py
@@ -40,10 +40,9 @@ in a Git repository for use during future 'repo init' invocations.
     helptext = self._helpDescription + '\n'
     r = os.path.dirname(__file__)
     r = os.path.dirname(r)
-    fd = open(os.path.join(r, 'docs', 'manifest-format.md'))
-    for line in fd:
-      helptext += line
-    fd.close()
+    with open(os.path.join(r, 'docs', 'manifest-format.md')) as fd:
+      for line in fd:
+        helptext += line
     return helptext
 
   def _Options(self, p):
diff --git a/subcmds/sync.py b/subcmds/sync.py
index f77a785b..9b4a6147 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -692,11 +692,8 @@ later is required to fix a server side protocol bug.
     old_project_paths = []
 
     if os.path.exists(file_path):
-      fd = open(file_path, 'r')
-      try:
+      with open(file_path, 'r') as fd:
         old_project_paths = fd.read().split('\n')
-      finally:
-        fd.close()
       # In reversed order, so subfolders are deleted before parent folder.
       for path in sorted(old_project_paths, reverse=True):
         if not path:
@@ -731,12 +728,9 @@ later is required to fix a server side protocol bug.
               return 1
 
     new_project_paths.sort()
-    fd = open(file_path, 'w')
-    try:
+    with open(file_path, 'w') as fd:
       fd.write('\n'.join(new_project_paths))
       fd.write('\n')
-    finally:
-      fd.close()
     return 0
 
   def _SmartSyncSetup(self, opt, smart_sync_manifest_path):
@@ -809,11 +803,8 @@ later is required to fix a server side protocol bug.
       if success:
         manifest_name = os.path.basename(smart_sync_manifest_path)
         try:
-          f = open(smart_sync_manifest_path, 'w')
-          try:
+          with open(smart_sync_manifest_path, 'w') as f:
             f.write(manifest_str)
-          finally:
-            f.close()
         except IOError as e:
           print('error: cannot write manifest to %s:\n%s'
                 % (smart_sync_manifest_path, e),
@@ -1102,11 +1093,8 @@ class _FetchTimes(object):
   def _Load(self):
     if self._times is None:
       try:
-        f = open(self._path)
-        try:
+        with open(self._path) as f:
           self._times = json.load(f)
-        finally:
-          f.close()
       except (IOError, ValueError):
         try:
           platform_utils.remove(self._path)
@@ -1126,11 +1114,8 @@ class _FetchTimes(object):
       del self._times[name]
 
     try:
-      f = open(self._path, 'w')
-      try:
+      with open(self._path, 'w') as f:
         json.dump(self._times, f, indent=2)
-      finally:
-        f.close()
     except (IOError, TypeError):
       try:
         platform_utils.remove(self._path)