Made more extensive usage of context managers with open.

django/core/cache/backends/filebased.py

@@ -31,16 +31,13 @@ class FileBasedCache(BaseCache):
 
         fname = self._key_to_file(key)
         try:
-            f = open(fname, 'rb')
-            try:
+            with open(fname, 'rb') as f:
                 exp = pickle.load(f)
                 now = time.time()
                 if exp < now:
                     self._delete(fname)
                 else:
                     return pickle.load(f)
-            finally:
-                f.close()
         except (IOError, OSError, EOFError, pickle.PickleError):
             pass
         return default
@@ -61,13 +58,10 @@ class FileBasedCache(BaseCache):
             if not os.path.exists(dirname):
                 os.makedirs(dirname)
 
-            f = open(fname, 'wb')
-            try:
+            with open(fname, 'wb') as f:
                 now = time.time()
                 pickle.dump(now + timeout, f, pickle.HIGHEST_PROTOCOL)
                 pickle.dump(value, f, pickle.HIGHEST_PROTOCOL)
-            finally:
-                f.close()
         except (IOError, OSError):
             pass
 
@@ -94,17 +88,14 @@ class FileBasedCache(BaseCache):
         self.validate_key(key)
         fname = self._key_to_file(key)
         try:
-            f = open(fname, 'rb')
-            try:
+            with open(fname, 'rb') as f:
                 exp = pickle.load(f)
-                now = time.time()
-                if exp < now:
-                    self._delete(fname)
-                    return False
-                else:
-                    return True
-            finally:
-                f.close()
+            now = time.time()
+            if exp < now:
+                self._delete(fname)
+                return False
+            else:
+                return True
         except (IOError, OSError, EOFError, pickle.PickleError):
             return False
 

django/core/files/locks.py

@@ -9,10 +9,9 @@ Cookbook, licensed under the Python Software License.
 Example Usage::
 
     >>> from django.core.files import locks
-    >>> f = open('./file', 'wb')
-    >>> locks.lock(f, locks.LOCK_EX)
-    >>> f.write('Django')
-    >>> f.close()
+    >>> with open('./file', 'wb') as f:
+    >>>     locks.lock(f, locks.LOCK_EX)
+    >>>     f.write('Django')
 """
 
 __all__ = ('LOCK_EX','LOCK_SH','LOCK_NB','lock','unlock')

django/core/files/move.py

@@ -59,8 +59,7 @@ def file_move_safe(old_file_name, new_file_name, chunk_size = 1024*64, allow_ove
         pass
 
     # first open the old file, so that it won't go away
-    old_file = open(old_file_name, 'rb')
-    try:
+    with open(old_file_name, 'rb') as old_file:
         # now open the new file, not forgetting allow_overwrite
         fd = os.open(new_file_name, os.O_WRONLY | os.O_CREAT | getattr(os, 'O_BINARY', 0) |
                                     (not allow_overwrite and os.O_EXCL or 0))
@@ -73,8 +72,6 @@ def file_move_safe(old_file_name, new_file_name, chunk_size = 1024*64, allow_ove
         finally:
             locks.unlock(fd)
             os.close(fd)
-    finally:
-        old_file.close()
     copystat(old_file_name, new_file_name)
 
     try:

django/core/mail/message.py

@@ -265,7 +265,8 @@ class EmailMessage(object):
     def attach_file(self, path, mimetype=None):
         """Attaches a file from the filesystem."""
         filename = os.path.basename(path)
-        content = open(path, 'rb').read()
+        with open(path, 'rb') as f:
+            content = f.read()
         self.attach(filename, content, mimetype)
 
     def _create_message(self, msg):

django/core/management/commands/compilemessages.py

@@ -5,8 +5,8 @@ from optparse import make_option
 from django.core.management.base import BaseCommand, CommandError
 
 def has_bom(fn):
-    f = open(fn, 'r')
-    sample = f.read(4)
+    with open(fn, 'r') as f:
+        sample = f.read(4)
     return sample[:3] == '\xef\xbb\xbf' or \
             sample.startswith(codecs.BOM_UTF16_LE) or \
             sample.startswith(codecs.BOM_UTF16_BE)

django/core/management/commands/makemessages.py

@@ -112,7 +112,8 @@ def copy_plural_forms(msgs, locale, domain, verbosity, stdout=sys.stdout):
     for domain in domains:
         django_po = os.path.join(django_dir, 'conf', 'locale', locale, 'LC_MESSAGES', '%s.po' % domain)
         if os.path.exists(django_po):
-            m = plural_forms_re.search(open(django_po, 'rU').read())
+            with open(django_po, 'rU') as fp:
+                m = plural_forms_re.search(fp.read())
             if m:
                 if verbosity > 1:
                     stdout.write("copying plural forms: %s\n" % m.group('value'))
@@ -141,11 +142,8 @@ def write_pot_file(potfile, msgs, file, work_file, is_templatized):
         msgs = '\n'.join(dropwhile(len, msgs.split('\n')))
     else:
         msgs = msgs.replace('charset=CHARSET', 'charset=UTF-8')
-    f = open(potfile, 'ab')
-    try:
-        f.write(msgs)
-    finally:
-        f.close()
+    with open(potfile, 'ab') as fp:
+        fp.write(msgs)
 
 def process_file(file, dirpath, potfile, domain, verbosity,
                  extensions, wrap, location, stdout=sys.stdout):
@@ -164,15 +162,13 @@ def process_file(file, dirpath, potfile, domain, verbosity,
     if domain == 'djangojs' and file_ext in extensions:
         is_templatized = True
         orig_file = os.path.join(dirpath, file)
-        src_data = open(orig_file).read()
+        with open(orig_file) as fp:
+            src_data = fp.read()
         src_data = prepare_js_for_gettext(src_data)
         thefile = '%s.c' % file
         work_file = os.path.join(dirpath, thefile)
-        f = open(work_file, "w")
-        try:
-            f.write(src_data)
-        finally:
-            f.close()
+        with open(work_file, "w") as fp:
+            fp.write(src_data)
         cmd = (
             'xgettext -d %s -L C %s %s --keyword=gettext_noop '
             '--keyword=gettext_lazy --keyword=ngettext_lazy:1,2 '
@@ -184,14 +180,12 @@ def process_file(file, dirpath, potfile, domain, verbosity,
         orig_file = os.path.join(dirpath, file)
         is_templatized = file_ext in extensions
         if is_templatized:
-            src_data = open(orig_file, "rU").read()
+            with open(orig_file, "rU") as fp:
+                src_data = fp.read()
             thefile = '%s.py' % file
             content = templatize(src_data, orig_file[2:])
-            f = open(os.path.join(dirpath, thefile), "w")
-            try:
-                f.write(content)
-            finally:
-                f.close()
+            with open(os.path.join(dirpath, thefile), "w") as fp:
+                fp.write(content)
         work_file = os.path.join(dirpath, thefile)
         cmd = (
             'xgettext -d %s -L Python %s %s --keyword=gettext_noop '
@@ -232,11 +226,8 @@ def write_po_file(pofile, potfile, domain, locale, verbosity, stdout,
         os.unlink(potfile)
         raise CommandError("errors happened while running msguniq\n%s" % errors)
     if os.path.exists(pofile):
-        f = open(potfile, 'w')
-        try:
-            f.write(msgs)
-        finally:
-            f.close()
+        with open(potfile, 'w') as fp:
+            fp.write(msgs)
         msgs, errors = _popen('msgmerge %s %s -q "%s" "%s"' %
                                 (wrap, location, pofile, potfile))
         if errors:
@@ -247,11 +238,8 @@ def write_po_file(pofile, potfile, domain, locale, verbosity, stdout,
         msgs = copy_plural_forms(msgs, locale, domain, verbosity, stdout)
     msgs = msgs.replace(
         "#. #-#-#-#-#  %s.pot (PACKAGE VERSION)  #-#-#-#-#\n" % domain, "")
-    f = open(pofile, 'wb')
-    try:
-        f.write(msgs)
-    finally:
-        f.close()
+    with open(pofile, 'wb') as fp:
+        fp.write(msgs)
     os.unlink(potfile)
     if no_obsolete:
         msgs, errors = _popen('msgattrib %s %s -o "%s" --no-obsolete "%s"' %

django/core/management/sql.py

@@ -157,13 +157,12 @@ def custom_sql_for_model(model, style, connection):
                  os.path.join(app_dir, "%s.sql" % opts.object_name.lower())]
     for sql_file in sql_files:
         if os.path.exists(sql_file):
-            fp = open(sql_file, 'U')
-            for statement in statements.split(fp.read().decode(settings.FILE_CHARSET)):
-                # Remove any comments from the file
-                statement = re.sub(ur"--.*([\n\Z]|$)", "", statement)
-                if statement.strip():
-                    output.append(statement + u";")
-            fp.close()
+            with open(sql_file, 'U') as fp:
+                for statement in statements.split(fp.read().decode(settings.FILE_CHARSET)):
+                    # Remove any comments from the file
+                    statement = re.sub(ur"--.*([\n\Z]|$)", "", statement)
+                    if statement.strip():
+                        output.append(statement + u";")
 
     return output
 

django/core/servers/fastcgi.py

@@ -176,9 +176,8 @@ def runfastcgi(argset=[], **kwargs):
         become_daemon(our_home_dir=options["workdir"], **daemon_kwargs)
 
     if options["pidfile"]:
-        fp = open(options["pidfile"], "w")
-        fp.write("%d\n" % os.getpid())
-        fp.close()
+        with open(options["pidfile"], "w") as fp:
+            fp.write("%d\n" % os.getpid())
 
     WSGIServer(get_internal_wsgi_application(), **wsgi_opts).run()