Explicitly close some files (from issue #10093)

Lib/base64.py

@@ -383,7 +383,8 @@ def main():
         if o == '-u': func = decode
         if o == '-t': test(); return
     if args and args[0] != '-':
-        func(open(args[0], 'rb'), sys.stdout.buffer)
+        with open(args[0], 'rb') as f:
+            func(f, sys.stdout.buffer)
     else:
         func(sys.stdin.buffer, sys.stdout.buffer)
 

Lib/mimetypes.py

@@ -199,9 +199,8 @@ class MimeTypes:
         list of standard types, else to the list of non-standard
         types.
         """
-        fp = open(filename)
-        self.readfp(fp, strict)
-        fp.close()
+        with open(filename) as fp:
+            self.readfp(fp, strict)
 
     def readfp(self, fp, strict=True):
         """
@@ -348,7 +347,7 @@ def init(files=None):
         files = knownfiles
     for file in files:
         if os.path.isfile(file):
-            db.readfp(open(file))
+            db.read(file)
     encodings_map = db.encodings_map
     suffix_map = db.suffix_map
     types_map = db.types_map[True]

Lib/sysconfig.py

@@ -333,7 +333,8 @@ def _init_posix(vars):
     # load the installed pyconfig.h:
     config_h = get_config_h_filename()
     try:
-        parse_config_h(open(config_h), vars)
+        with open(config_h) as f:
+            parse_config_h(f, vars)
     except IOError as e:
         msg = "invalid Python installation: unable to open %s" % config_h
         if hasattr(e, "strerror"):

Lib/test/test_argparse.py

@@ -4160,7 +4160,8 @@ class TestEncoding(TestCase):
     def _test_module_encoding(self, path):
         path, _ = os.path.splitext(path)
         path += ".py"
-        codecs.open(path, 'r', 'utf8').read()
+        with codecs.open(path, 'r', 'utf8') as f:
+            f.read()
 
     def test_argparse_module_encoding(self):
         self._test_module_encoding(argparse.__file__)

Lib/test/test_xml_etree.py

@@ -602,10 +602,13 @@ def parsefile():
        <ns0:empty-element />
     </ns0:root>
 
+    >>> with open(SIMPLE_XMLFILE) as f:
+    ...     data = f.read()
+
     >>> parser = ET.XMLParser()
     >>> parser.version  # doctest: +ELLIPSIS
     'Expat ...'
-    >>> parser.feed(open(SIMPLE_XMLFILE).read())
+    >>> parser.feed(data)
     >>> print(serialize(parser.close()))
     <root>
        <element key="value">text</element>
@@ -614,7 +617,7 @@ def parsefile():
     </root>
 
     >>> parser = ET.XMLTreeBuilder() # 1.2 compatibility
-    >>> parser.feed(open(SIMPLE_XMLFILE).read())
+    >>> parser.feed(data)
     >>> print(serialize(parser.close()))
     <root>
        <element key="value">text</element>
@@ -624,7 +627,7 @@ def parsefile():
 
     >>> target = ET.TreeBuilder()
     >>> parser = ET.XMLParser(target=target)
-    >>> parser.feed(open(SIMPLE_XMLFILE).read())
+    >>> parser.feed(data)
     >>> print(serialize(parser.close()))
     <root>
        <element key="value">text</element>
@@ -727,7 +730,8 @@ def iterparse():
     end-ns None
 
     >>> events = ("start", "end", "bogus")
-    >>> context = iterparse(SIMPLE_XMLFILE, events)
+    >>> with open(SIMPLE_XMLFILE, "rb") as f:
+    ...     iterparse(f, events)
     Traceback (most recent call last):
     ValueError: unknown event 'bogus'
 
@@ -779,6 +783,8 @@ def custom_builder():
     """
     Test parser w. custom builder.
 
+    >>> with open(SIMPLE_XMLFILE) as f:
+    ...     data = f.read()
     >>> class Builder:
     ...     def start(self, tag, attrib):
     ...         print("start", tag)
@@ -788,7 +794,7 @@ def custom_builder():
     ...         pass
     >>> builder = Builder()
     >>> parser = ET.XMLParser(target=builder)
-    >>> parser.feed(open(SIMPLE_XMLFILE, "r").read())
+    >>> parser.feed(data)
     start root
     start element
     end element
@@ -798,6 +804,8 @@ def custom_builder():
     end empty-element
     end root
 
+    >>> with open(SIMPLE_NS_XMLFILE) as f:
+    ...     data = f.read()
     >>> class Builder:
     ...     def start(self, tag, attrib):
     ...         print("start", tag)
@@ -811,7 +819,7 @@ def custom_builder():
     ...         print("comment", repr(data))
     >>> builder = Builder()
     >>> parser = ET.XMLParser(target=builder)
-    >>> parser.feed(open(SIMPLE_NS_XMLFILE, "r").read())
+    >>> parser.feed(data)
     pi pi 'data'
     comment ' comment '
     start {namespace}root
@@ -829,7 +837,8 @@ def getchildren():
     """
     Test Element.getchildren()
 
-    >>> tree = ET.parse(open(SIMPLE_XMLFILE, "rb"))
+    >>> with open(SIMPLE_XMLFILE, "rb") as f:
+    ...     tree = ET.parse(f)
     >>> for elem in tree.getroot().iter():
     ...     summarize_list(elem.getchildren())
     ['element', 'element', 'empty-element']

Python/traceback.c

@@ -208,6 +208,7 @@ _Py_DisplaySourceLine(PyObject *f, PyObject *filename, int lineno, int indent)
     PyObject *binary;
     PyObject *fob = NULL;
     PyObject *lineobj = NULL;
+    PyObject *res;
     char buf[MAXPATHLEN+1];
     Py_UNICODE *u, *p;
     Py_ssize_t len;
@@ -253,6 +254,11 @@ _Py_DisplaySourceLine(PyObject *f, PyObject *filename, int lineno, int indent)
             break;
         }
     }
+    res = PyObject_CallMethod(fob, "close", "");
+    if (res)
+        Py_DECREF(res);
+    else
+        PyErr_Clear();
     Py_DECREF(fob);
     if (!lineobj || !PyUnicode_Check(lineobj)) {
         Py_XDECREF(lineobj);