Properly close some leaked resources.

IPython/utils/openpy.py

@@ -1,105 +1,105 b''
 """
 Tools to open .py files as Unicode, using the encoding specified within the file,
 as per PEP 263.
 
 Much of the code is taken from the tokenize module in Python 3.2.
 """
 
 import io
 from io import TextIOWrapper, BytesIO
 import re
 from tokenize import open, detect_encoding
 
 cookie_re = re.compile(r"coding[:=]\s*([-\w.]+)", re.UNICODE)
 cookie_comment_re = re.compile(r"^\s*#.*coding[:=]\s*([-\w.]+)", re.UNICODE)
 
 def source_to_unicode(txt, errors='replace', skip_encoding_cookie=True):
     """Converts a bytes string with python source code to unicode.
 
     Unicode strings are passed through unchanged. Byte strings are checked
     for the python source file encoding cookie to determine encoding.
     txt can be either a bytes buffer or a string containing the source
     code.
     """
     if isinstance(txt, str):
         return txt
     if isinstance(txt, bytes):
         buffer = BytesIO(txt)
     else:
         buffer = txt
     try:
         encoding, _ = detect_encoding(buffer.readline)
     except SyntaxError:
         encoding = "ascii"
     buffer.seek(0)
-    text = TextIOWrapper(buffer, encoding, errors=errors, line_buffering=True)
-    text.mode = 'r'
-    if skip_encoding_cookie:
-        return u"".join(strip_encoding_cookie(text))
-    else:
-        return text.read()
+    with TextIOWrapper(buffer, encoding, errors=errors, line_buffering=True) as text:
+        text.mode = 'r'
+        if skip_encoding_cookie:
+            return u"".join(strip_encoding_cookie(text))
+        else:
+            return text.read()
 
 def strip_encoding_cookie(filelike):
     """Generator to pull lines from a text-mode file, skipping the encoding
     cookie if it is found in the first two lines.
     """
     it = iter(filelike)
     try:
         first = next(it)
         if not cookie_comment_re.match(first):
             yield first
         second = next(it)
         if not cookie_comment_re.match(second):
             yield second
     except StopIteration:
         return
     
     for line in it:
         yield line
 
 def read_py_file(filename, skip_encoding_cookie=True):
     """Read a Python file, using the encoding declared inside the file.
     
     Parameters
     ----------
     filename : str
       The path to the file to read.
     skip_encoding_cookie : bool
       If True (the default), and the encoding declaration is found in the first
       two lines, that line will be excluded from the output - compiling a
       unicode string with an encoding declaration is a SyntaxError in Python 2.
     
     Returns
     -------
     A unicode string containing the contents of the file.
     """
     with open(filename) as f:   # the open function defined in this module.
         if skip_encoding_cookie:
             return "".join(strip_encoding_cookie(f))
         else:
             return f.read()
 
 def read_py_url(url, errors='replace', skip_encoding_cookie=True):
     """Read a Python file from a URL, using the encoding declared inside the file.
     
     Parameters
     ----------
     url : str
       The URL from which to fetch the file.
     errors : str
       How to handle decoding errors in the file. Options are the same as for
       bytes.decode(), but here 'replace' is the default.
     skip_encoding_cookie : bool
       If True (the default), and the encoding declaration is found in the first
       two lines, that line will be excluded from the output - compiling a
       unicode string with an encoding declaration is a SyntaxError in Python 2.
     
     Returns
     -------
     A unicode string containing the contents of the file.
     """
     # Deferred import for faster start
     from urllib.request import urlopen 
     response = urlopen(url)
     buffer = io.BytesIO(response.read())
     return source_to_unicode(buffer, errors, skip_encoding_cookie)