bpo-22831: Use "with" to avoid possible fd leaks in distutils. (GH-10921)

Lib/distutils/command/bdist_msi.py

@@ -390,18 +390,18 @@ class bdist_msi(Command):
         #     entries for each version as the above code does
         if self.pre_install_script:
             scriptfn = os.path.join(self.bdist_dir, "preinstall.bat")
-            f = open(scriptfn, "w")
-            # The batch file will be executed with [PYTHON], so that %1
-            # is the path to the Python interpreter; %0 will be the path
-            # of the batch file.
-            # rem ="""
-            # %1 %0
-            # exit
-            # """
-            # <actual script>
-            f.write('rem ="""\n%1 %0\nexit\n"""\n')
-            f.write(open(self.pre_install_script).read())
-            f.close()
+            with open(scriptfn, "w") as f:
+                # The batch file will be executed with [PYTHON], so that %1
+                # is the path to the Python interpreter; %0 will be the path
+                # of the batch file.
+                # rem ="""
+                # %1 %0
+                # exit
+                # """
+                # <actual script>
+                f.write('rem ="""\n%1 %0\nexit\n"""\n')
+                with open(self.pre_install_script) as fin:
+                    f.write(fin.read())
             add_data(self.db, "Binary",
                 [("PreInstall", msilib.Binary(scriptfn))
                 ])

Lib/distutils/command/config.py

@@ -106,15 +106,14 @@ class config(Command):
 
     def _gen_temp_sourcefile(self, body, headers, lang):
         filename = "_configtest" + LANG_EXT[lang]
-        file = open(filename, "w")
-        if headers:
-            for header in headers:
-                file.write("#include <%s>\n" % header)
-            file.write("\n")
-        file.write(body)
-        if body[-1] != "\n":
-            file.write("\n")
-        file.close()
+        with open(filename, "w") as file:
+            if headers:
+                for header in headers:
+                    file.write("#include <%s>\n" % header)
+                file.write("\n")
+            file.write(body)
+            if body[-1] != "\n":
+                file.write("\n")
         return filename
 
     def _preprocess(self, body, headers, include_dirs, lang):
@@ -203,17 +202,16 @@ class config(Command):
         if isinstance(pattern, str):
             pattern = re.compile(pattern)
 
-        file = open(out)
-        match = False
-        while True:
-            line = file.readline()
-            if line == '':
-                break
-            if pattern.search(line):
-                match = True
-                break
+        with open(out) as file:
+            match = False
+            while True:
+                line = file.readline()
+                if line == '':
+                    break
+                if pattern.search(line):
+                    match = True
+                    break
 
-        file.close()
         self._clean()
         return match
 

Lib/distutils/command/sdist.py

@@ -407,14 +407,13 @@ class sdist(Command):
         distribution.
         """
         log.info("reading manifest file '%s'", self.manifest)
-        manifest = open(self.manifest)
-        for line in manifest:
-            # ignore comments and blank lines
-            line = line.strip()
-            if line.startswith('#') or not line:
-                continue
-            self.filelist.append(line)
-        manifest.close()
+        with open(self.manifest) as manifest:
+            for line in manifest:
+                # ignore comments and blank lines
+                line = line.strip()
+                if line.startswith('#') or not line:
+                    continue
+                self.filelist.append(line)
 
     def make_release_tree(self, base_dir, files):
         """Create the directory tree that will become the source