Merge pull request #11792 from Carreau/textiowrapperleak

Properly close some leaked resources.

IPython/testing/tests/test_tools.py

@@ -1,136 +1,135
 # encoding: utf-8
 """
 Tests for testing.tools
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import unittest
 
 import nose.tools as nt
 
 from IPython.testing import decorators as dec
 from IPython.testing import tools as tt
 
 #-----------------------------------------------------------------------------
 # Tests
 #-----------------------------------------------------------------------------
 
 @dec.skip_win32
 def test_full_path_posix():
     spath = '/foo/bar.py'
     result = tt.full_path(spath,['a.txt','b.txt'])
     nt.assert_equal(result, ['/foo/a.txt', '/foo/b.txt'])
     spath = '/foo'
     result = tt.full_path(spath,['a.txt','b.txt'])
     nt.assert_equal(result, ['/a.txt', '/b.txt'])
     result = tt.full_path(spath,'a.txt')
     nt.assert_equal(result, ['/a.txt'])
 
 
 @dec.skip_if_not_win32
 def test_full_path_win32():
     spath = 'c:\\foo\\bar.py'
     result = tt.full_path(spath,['a.txt','b.txt'])
     nt.assert_equal(result, ['c:\\foo\\a.txt', 'c:\\foo\\b.txt'])
     spath = 'c:\\foo'
     result = tt.full_path(spath,['a.txt','b.txt'])
     nt.assert_equal(result, ['c:\\a.txt', 'c:\\b.txt'])
     result = tt.full_path(spath,'a.txt')
     nt.assert_equal(result, ['c:\\a.txt'])
 
     
 def test_parser():
     err = ("FAILED (errors=1)", 1, 0)
     fail = ("FAILED (failures=1)", 0, 1)
     both = ("FAILED (errors=1, failures=1)", 1, 1)
     for txt, nerr, nfail in [err, fail, both]:
         nerr1, nfail1 = tt.parse_test_output(txt)
         nt.assert_equal(nerr, nerr1)
         nt.assert_equal(nfail, nfail1)
 
 
 def test_temp_pyfile():
     src = 'pass\n'
-    fname, fh = tt.temp_pyfile(src)
+    fname = tt.temp_pyfile(src)
     assert os.path.isfile(fname)
-    fh.close()
     with open(fname) as fh2:
         src2 = fh2.read()
     nt.assert_equal(src2, src)
 
 class TestAssertPrints(unittest.TestCase):
     def test_passing(self):
         with tt.AssertPrints("abc"):
             print("abcd")
             print("def")
             print(b"ghi")
     
     def test_failing(self):
         def func():
             with tt.AssertPrints("abc"):
                 print("acd")
                 print("def")
                 print(b"ghi")
         
         self.assertRaises(AssertionError, func)
 
 
 class Test_ipexec_validate(unittest.TestCase, tt.TempFileMixin):
     def test_main_path(self):
         """Test with only stdout results.
         """
         self.mktmp("print('A')\n"
                    "print('B')\n"
                    )
         out = "A\nB"
         tt.ipexec_validate(self.fname, out)
 
     def test_main_path2(self):
         """Test with only stdout results, expecting windows line endings.
         """
         self.mktmp("print('A')\n"
                    "print('B')\n"
                    )
         out = "A\r\nB"
         tt.ipexec_validate(self.fname, out)
 
     def test_exception_path(self):
         """Test exception path in exception_validate.
         """
         self.mktmp("import sys\n"
                    "print('A')\n"
                    "print('B')\n"
                    "print('C', file=sys.stderr)\n"
                    "print('D', file=sys.stderr)\n"
                    )
         out = "A\nB"
         tt.ipexec_validate(self.fname, expected_out=out, expected_err="C\nD")
 
     def test_exception_path2(self):
         """Test exception path in exception_validate, expecting windows line endings.
         """
         self.mktmp("import sys\n"
                    "print('A')\n"
                    "print('B')\n"
                    "print('C', file=sys.stderr)\n"
                    "print('D', file=sys.stderr)\n"
                    )
         out = "A\r\nB"
         tt.ipexec_validate(self.fname, expected_out=out, expected_err="C\r\nD")
 
 
     def tearDown(self):
         # tear down correctly the mixin,
         # unittest.TestCase.tearDown does nothing
         tt.TempFileMixin.tearDown(self)

IPython/testing/tools.py

@@ -1,471 +1,470
 """Generic testing tools.
 
 Authors
 -------
 - Fernando Perez <[e-mail]>
 """
 
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import os
 import re
 import sys
 import tempfile
 
 from contextlib import contextmanager
 from io import StringIO
 from subprocess import Popen, PIPE
 from unittest.mock import patch
 
 try:
     # These tools are used by parts of the runtime, so we make the nose
     # dependency optional at this point.  Nose is a hard dependency to run the
     # test suite, but NOT to use ipython itself.
     import nose.tools as nt
     has_nose = True
 except ImportError:
     has_nose = False
 
 from traitlets.config.loader import Config
 from IPython.utils.process import get_output_error_code
 from IPython.utils.text import list_strings
 from IPython.utils.io import temp_pyfile, Tee
 from IPython.utils import py3compat
 
 from . import decorators as dec
 from . import skipdoctest
 
 
 # The docstring for full_path doctests differently on win32 (different path
 # separator) so just skip the doctest there.  The example remains informative.
 doctest_deco = skipdoctest.skip_doctest if sys.platform == 'win32' else dec.null_deco
 
 @doctest_deco
 def full_path(startPath,files):
     """Make full paths for all the listed files, based on startPath.
 
     Only the base part of startPath is kept, since this routine is typically
     used with a script's ``__file__`` variable as startPath. The base of startPath
     is then prepended to all the listed files, forming the output list.
 
     Parameters
     ----------
     startPath : string
       Initial path to use as the base for the results.  This path is split
       using os.path.split() and only its first component is kept.
 
     files : string or list
       One or more files.
 
     Examples
     --------
 
     >>> full_path('/foo/bar.py',['a.txt','b.txt'])
     ['/foo/a.txt', '/foo/b.txt']
 
     >>> full_path('/foo',['a.txt','b.txt'])
     ['/a.txt', '/b.txt']
 
     If a single file is given, the output is still a list::
 
         >>> full_path('/foo','a.txt')
         ['/a.txt']
     """
 
     files = list_strings(files)
     base = os.path.split(startPath)[0]
     return [ os.path.join(base,f) for f in files ]
 
 
 def parse_test_output(txt):
     """Parse the output of a test run and return errors, failures.
 
     Parameters
     ----------
     txt : str
       Text output of a test run, assumed to contain a line of one of the
       following forms::
 
         'FAILED (errors=1)'
         'FAILED (failures=1)'
         'FAILED (errors=1, failures=1)'
 
     Returns
     -------
     nerr, nfail
       number of errors and failures.
     """
 
     err_m = re.search(r'^FAILED \(errors=(\d+)\)', txt, re.MULTILINE)
     if err_m:
         nerr = int(err_m.group(1))
         nfail = 0
         return  nerr, nfail
 
     fail_m = re.search(r'^FAILED \(failures=(\d+)\)', txt, re.MULTILINE)
     if fail_m:
         nerr = 0
         nfail = int(fail_m.group(1))
         return  nerr, nfail
 
     both_m = re.search(r'^FAILED \(errors=(\d+), failures=(\d+)\)', txt,
                        re.MULTILINE)
     if both_m:
         nerr = int(both_m.group(1))
         nfail = int(both_m.group(2))
         return  nerr, nfail
 
     # If the input didn't match any of these forms, assume no error/failures
     return 0, 0
 
 
 # So nose doesn't think this is a test
 parse_test_output.__test__ = False
 
 
 def default_argv():
     """Return a valid default argv for creating testing instances of ipython"""
 
     return ['--quick', # so no config file is loaded
             # Other defaults to minimize side effects on stdout
             '--colors=NoColor', '--no-term-title','--no-banner',
             '--autocall=0']
 
 
 def default_config():
     """Return a config object with good defaults for testing."""
     config = Config()
     config.TerminalInteractiveShell.colors = 'NoColor'
     config.TerminalTerminalInteractiveShell.term_title = False,
     config.TerminalInteractiveShell.autocall = 0
     f = tempfile.NamedTemporaryFile(suffix=u'test_hist.sqlite', delete=False)
     config.HistoryManager.hist_file = f.name
     f.close()
     config.HistoryManager.db_cache_size = 10000
     return config
 
 
 def get_ipython_cmd(as_string=False):
     """
     Return appropriate IPython command line name. By default, this will return
     a list that can be used with subprocess.Popen, for example, but passing
     `as_string=True` allows for returning the IPython command as a string.
 
     Parameters
     ----------
     as_string: bool
         Flag to allow to return the command as a string.
     """
     ipython_cmd = [sys.executable, "-m", "IPython"]
 
     if as_string:
         ipython_cmd = " ".join(ipython_cmd)
 
     return ipython_cmd
 
 def ipexec(fname, options=None, commands=()):
     """Utility to call 'ipython filename'.
 
     Starts IPython with a minimal and safe configuration to make startup as fast
     as possible.
 
     Note that this starts IPython in a subprocess!
 
     Parameters
     ----------
     fname : str
       Name of file to be executed (should have .py or .ipy extension).
 
     options : optional, list
       Extra command-line flags to be passed to IPython.
 
     commands : optional, list
       Commands to send in on stdin
 
     Returns
     -------
     ``(stdout, stderr)`` of ipython subprocess.
     """
     if options is None: options = []
 
     cmdargs = default_argv() + options
 
     test_dir = os.path.dirname(__file__)
 
     ipython_cmd = get_ipython_cmd()
     # Absolute path for filename
     full_fname = os.path.join(test_dir, fname)
     full_cmd = ipython_cmd + cmdargs + [full_fname]
     env = os.environ.copy()
     # FIXME: ignore all warnings in ipexec while we have shims
     # should we keep suppressing warnings here, even after removing shims?
     env['PYTHONWARNINGS'] = 'ignore'
     # env.pop('PYTHONWARNINGS', None)  # Avoid extraneous warnings appearing on stderr
     for k, v in env.items():
         # Debug a bizarre failure we've seen on Windows:
         # TypeError: environment can only contain strings
         if not isinstance(v, str):
             print(k, v)
     p = Popen(full_cmd, stdout=PIPE, stderr=PIPE, stdin=PIPE, env=env)
     out, err = p.communicate(input=py3compat.encode('\n'.join(commands)) or None)
     out, err = py3compat.decode(out), py3compat.decode(err)
     # `import readline` causes 'ESC[?1034h' to be output sometimes,
     # so strip that out before doing comparisons
     if out:
         out = re.sub(r'\x1b\[[^h]+h', '', out)
     return out, err
 
 
 def ipexec_validate(fname, expected_out, expected_err='',
                     options=None, commands=()):
     """Utility to call 'ipython filename' and validate output/error.
 
     This function raises an AssertionError if the validation fails.
 
     Note that this starts IPython in a subprocess!
 
     Parameters
     ----------
     fname : str
       Name of the file to be executed (should have .py or .ipy extension).
 
     expected_out : str
       Expected stdout of the process.
 
     expected_err : optional, str
       Expected stderr of the process.
 
     options : optional, list
       Extra command-line flags to be passed to IPython.
 
     Returns
     -------
     None
     """
 
     import nose.tools as nt
 
     out, err = ipexec(fname, options, commands)
     #print 'OUT', out  # dbg
     #print 'ERR', err  # dbg
     # If there are any errors, we must check those before stdout, as they may be
     # more informative than simply having an empty stdout.
     if err:
         if expected_err:
             nt.assert_equal("\n".join(err.strip().splitlines()), "\n".join(expected_err.strip().splitlines()))
         else:
             raise ValueError('Running file %r produced error: %r' %
                              (fname, err))
     # If no errors or output on stderr was expected, match stdout
     nt.assert_equal("\n".join(out.strip().splitlines()), "\n".join(expected_out.strip().splitlines()))
 
 
 class TempFileMixin(object):
     """Utility class to create temporary Python/IPython files.
 
     Meant as a mixin class for test cases."""
 
     def mktmp(self, src, ext='.py'):
         """Make a valid python temp file."""
-        fname, f = temp_pyfile(src, ext)
+        fname = temp_pyfile(src, ext)
         if not hasattr(self, 'tmps'):
             self.tmps=[]
-        self.tmps.append((f, fname))
+        self.tmps.append(fname)
         self.fname = fname
 
     def tearDown(self):
         # If the tmpfile wasn't made because of skipped tests, like in
         # win32, there's nothing to cleanup.
         if hasattr(self, 'tmps'):
-            for f,fname in self.tmps:
+            for fname in self.tmps:
                 # If the tmpfile wasn't made because of skipped tests, like in
                 # win32, there's nothing to cleanup.
-                f.close()
                 try:
                     os.unlink(fname)
                 except:
                     # On Windows, even though we close the file, we still can't
                     # delete it.  I have no clue why
                     pass
 
     def __enter__(self):
         return self
 
     def __exit__(self, exc_type, exc_value, traceback):
         self.tearDown()
 
 
 pair_fail_msg = ("Testing {0}\n\n"
                 "In:\n"
                 "  {1!r}\n"
                 "Expected:\n"
                 "  {2!r}\n"
                 "Got:\n"
                 "  {3!r}\n")
 def check_pairs(func, pairs):
     """Utility function for the common case of checking a function with a
     sequence of input/output pairs.
 
     Parameters
     ----------
     func : callable
       The function to be tested. Should accept a single argument.
     pairs : iterable
       A list of (input, expected_output) tuples.
 
     Returns
     -------
     None. Raises an AssertionError if any output does not match the expected
     value.
     """
     name = getattr(func, "func_name", getattr(func, "__name__", "<unknown>"))
     for inp, expected in pairs:
         out = func(inp)
         assert out == expected, pair_fail_msg.format(name, inp, expected, out)
 
 
 MyStringIO = StringIO
 
 _re_type = type(re.compile(r''))
 
 notprinted_msg = """Did not find {0!r} in printed output (on {1}):
 -------
 {2!s}
 -------
 """
 
 class AssertPrints(object):
     """Context manager for testing that code prints certain text.
 
     Examples
     --------
     >>> with AssertPrints("abc", suppress=False):
     ...     print("abcd")
     ...     print("def")
     ...
     abcd
     def
     """
     def __init__(self, s, channel='stdout', suppress=True):
         self.s = s
         if isinstance(self.s, (str, _re_type)):
             self.s = [self.s]
         self.channel = channel
         self.suppress = suppress
 
     def __enter__(self):
         self.orig_stream = getattr(sys, self.channel)
         self.buffer = MyStringIO()
         self.tee = Tee(self.buffer, channel=self.channel)
         setattr(sys, self.channel, self.buffer if self.suppress else self.tee)
 
     def __exit__(self, etype, value, traceback):
         try:
             if value is not None:
                 # If an error was raised, don't check anything else
                 return False
             self.tee.flush()
             setattr(sys, self.channel, self.orig_stream)
             printed = self.buffer.getvalue()
             for s in self.s:
                 if isinstance(s, _re_type):
                     assert s.search(printed), notprinted_msg.format(s.pattern, self.channel, printed)
                 else:
                     assert s in printed, notprinted_msg.format(s, self.channel, printed)
             return False
         finally:
             self.tee.close()
 
 printed_msg = """Found {0!r} in printed output (on {1}):
 -------
 {2!s}
 -------
 """
 
 class AssertNotPrints(AssertPrints):
     """Context manager for checking that certain output *isn't* produced.
 
     Counterpart of AssertPrints"""
     def __exit__(self, etype, value, traceback):
         try:
             if value is not None:
                 # If an error was raised, don't check anything else
                 self.tee.close()
                 return False
             self.tee.flush()
             setattr(sys, self.channel, self.orig_stream)
             printed = self.buffer.getvalue()
             for s in self.s:
                 if isinstance(s, _re_type):
                     assert not s.search(printed),printed_msg.format(
                         s.pattern, self.channel, printed)
                 else:
                     assert s not in printed, printed_msg.format(
                         s, self.channel, printed)
             return False
         finally:
             self.tee.close()
 
 @contextmanager
 def mute_warn():
     from IPython.utils import warn
     save_warn = warn.warn
     warn.warn = lambda *a, **kw: None
     try:
         yield
     finally:
         warn.warn = save_warn
 
 @contextmanager
 def make_tempfile(name):
     """ Create an empty, named, temporary file for the duration of the context.
     """
     open(name, 'w').close()
     try:
         yield
     finally:
         os.unlink(name)
 
 def fake_input(inputs):
     """Temporarily replace the input() function to return the given values
 
     Use as a context manager:
 
     with fake_input(['result1', 'result2']):
         ...
 
     Values are returned in order. If input() is called again after the last value
     was used, EOFError is raised.
     """
     it = iter(inputs)
     def mock_input(prompt=''):
         try:
             return next(it)
         except StopIteration:
             raise EOFError('No more inputs given')
 
     return patch('builtins.input', mock_input)
 
 def help_output_test(subcommand=''):
     """test that `ipython [subcommand] -h` works"""
     cmd = get_ipython_cmd() + [subcommand, '-h']
     out, err, rc = get_output_error_code(cmd)
     nt.assert_equal(rc, 0, err)
     nt.assert_not_in("Traceback", err)
     nt.assert_in("Options", out)
     nt.assert_in("--help-all", out)
     return out, err
 
 
 def help_all_output_test(subcommand=''):
     """test that `ipython [subcommand] --help-all` works"""
     cmd = get_ipython_cmd() + [subcommand, '--help-all']
     out, err, rc = get_output_error_code(cmd)
     nt.assert_equal(rc, 0, err)
     nt.assert_not_in("Traceback", err)
     nt.assert_in("Options", out)
     nt.assert_in("Class", out)
     return out, err
 

IPython/utils/io.py

@@ -1,248 +1,248
 # encoding: utf-8
 """
 IO related utilities.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 
 import atexit
 import os
 import sys
 import tempfile
 import warnings
 from warnings import warn
 
 from IPython.utils.decorators import undoc
 from .capture import CapturedIO, capture_output
 
 @undoc
 class IOStream:
 
     def __init__(self, stream, fallback=None):
         warn('IOStream is deprecated since IPython 5.0, use sys.{stdin,stdout,stderr} instead',
              DeprecationWarning, stacklevel=2)
         if not hasattr(stream,'write') or not hasattr(stream,'flush'):
             if fallback is not None:
                 stream = fallback
             else:
                 raise ValueError("fallback required, but not specified")
         self.stream = stream
         self._swrite = stream.write
 
         # clone all methods not overridden:
         def clone(meth):
             return not hasattr(self, meth) and not meth.startswith('_')
         for meth in filter(clone, dir(stream)):
             try:
                 val = getattr(stream, meth)
             except AttributeError:
                 pass
             else:
                 setattr(self, meth, val)
 
     def __repr__(self):
         cls = self.__class__
         tpl = '{mod}.{cls}({args})'
         return tpl.format(mod=cls.__module__, cls=cls.__name__, args=self.stream)
 
     def write(self,data):
         warn('IOStream is deprecated since IPython 5.0, use sys.{stdin,stdout,stderr} instead',
              DeprecationWarning, stacklevel=2)
         try:
             self._swrite(data)
         except:
             try:
                 # print handles some unicode issues which may trip a plain
                 # write() call.  Emulate write() by using an empty end
                 # argument.
                 print(data, end='', file=self.stream)
             except:
                 # if we get here, something is seriously broken.
                 print('ERROR - failed to write data to stream:', self.stream,
                       file=sys.stderr)
 
     def writelines(self, lines):
         warn('IOStream is deprecated since IPython 5.0, use sys.{stdin,stdout,stderr} instead',
              DeprecationWarning, stacklevel=2)
         if isinstance(lines, str):
             lines = [lines]
         for line in lines:
             self.write(line)
 
     # This class used to have a writeln method, but regular files and streams
     # in Python don't have this method. We need to keep this completely
     # compatible so we removed it.
 
     @property
     def closed(self):
         return self.stream.closed
 
     def close(self):
         pass
 
 # setup stdin/stdout/stderr to sys.stdin/sys.stdout/sys.stderr
 devnull = open(os.devnull, 'w')
 atexit.register(devnull.close)
 
 # io.std* are deprecated, but don't show our own deprecation warnings
 # during initialization of the deprecated API.
 with warnings.catch_warnings():
     warnings.simplefilter('ignore', DeprecationWarning)
     stdin = IOStream(sys.stdin, fallback=devnull)
     stdout = IOStream(sys.stdout, fallback=devnull)
     stderr = IOStream(sys.stderr, fallback=devnull)
 
 class Tee(object):
     """A class to duplicate an output stream to stdout/err.
 
     This works in a manner very similar to the Unix 'tee' command.
 
     When the object is closed or deleted, it closes the original file given to
     it for duplication.
     """
     # Inspired by:
     # http://mail.python.org/pipermail/python-list/2007-May/442737.html
 
     def __init__(self, file_or_name, mode="w", channel='stdout'):
         """Construct a new Tee object.
 
         Parameters
         ----------
         file_or_name : filename or open filehandle (writable)
           File that will be duplicated
 
         mode : optional, valid mode for open().
           If a filename was give, open with this mode.
 
         channel : str, one of ['stdout', 'stderr']
         """
         if channel not in ['stdout', 'stderr']:
             raise ValueError('Invalid channel spec %s' % channel)
 
         if hasattr(file_or_name, 'write') and hasattr(file_or_name, 'seek'):
             self.file = file_or_name
         else:
             self.file = open(file_or_name, mode)
         self.channel = channel
         self.ostream = getattr(sys, channel)
         setattr(sys, channel, self)
         self._closed = False
 
     def close(self):
         """Close the file and restore the channel."""
         self.flush()
         setattr(sys, self.channel, self.ostream)
         self.file.close()
         self._closed = True
 
     def write(self, data):
         """Write data to both channels."""
         self.file.write(data)
         self.ostream.write(data)
         self.ostream.flush()
 
     def flush(self):
         """Flush both channels."""
         self.file.flush()
         self.ostream.flush()
 
     def __del__(self):
         if not self._closed:
             self.close()
 
 
 def ask_yes_no(prompt, default=None, interrupt=None):
     """Asks a question and returns a boolean (y/n) answer.
 
     If default is given (one of 'y','n'), it is used if the user input is
     empty. If interrupt is given (one of 'y','n'), it is used if the user
     presses Ctrl-C. Otherwise the question is repeated until an answer is
     given.
 
     An EOF is treated as the default answer.  If there is no default, an
     exception is raised to prevent infinite loops.
 
     Valid answers are: y/yes/n/no (match is not case sensitive)."""
 
     answers = {'y':True,'n':False,'yes':True,'no':False}
     ans = None
     while ans not in answers.keys():
         try:
             ans = input(prompt+' ').lower()
             if not ans:  # response was an empty string
                 ans = default
         except KeyboardInterrupt:
             if interrupt:
                 ans = interrupt
             print("\r")
         except EOFError:
             if default in answers.keys():
                 ans = default
                 print()
             else:
                 raise
 
     return answers[ans]
 
 
 def temp_pyfile(src, ext='.py'):
     """Make a temporary python file, return filename and filehandle.
 
     Parameters
     ----------
     src : string or list of strings (no need for ending newlines if list)
       Source code to be written to the file.
 
     ext : optional, string
       Extension for the generated file.
 
     Returns
     -------
     (filename, open filehandle)
       It is the caller's responsibility to close the open file and unlink it.
     """
     fname = tempfile.mkstemp(ext)[1]
-    f = open(fname,'w')
-    f.write(src)
-    f.flush()
-    return fname, f
+    with open(fname,'w') as f:
+        f.write(src)
+        f.flush()
+    return fname
 
 @undoc
 def atomic_writing(*args, **kwargs):
     """DEPRECATED: moved to notebook.services.contents.fileio"""
     warn("IPython.utils.io.atomic_writing has moved to notebook.services.contents.fileio since IPython 4.0", DeprecationWarning, stacklevel=2)
     from notebook.services.contents.fileio import atomic_writing
     return atomic_writing(*args, **kwargs)
 
 @undoc
 def raw_print(*args, **kw):
     """DEPRECATED: Raw print to sys.__stdout__, otherwise identical interface to print()."""
     warn("IPython.utils.io.raw_print has been deprecated since IPython 7.0", DeprecationWarning, stacklevel=2)
 
     print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
           file=sys.__stdout__)
     sys.__stdout__.flush()
 
 @undoc
 def raw_print_err(*args, **kw):
     """DEPRECATED: Raw print to sys.__stderr__, otherwise identical interface to print()."""
     warn("IPython.utils.io.raw_print_err has been deprecated since IPython 7.0", DeprecationWarning, stacklevel=2)
 
     print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
           file=sys.__stderr__)
     sys.__stderr__.flush()
 
 # used by IPykernel <- 4.9. Removed during IPython 7-dev period and re-added 
 # Keep for a version or two then should remove
 rprint = raw_print
 rprinte = raw_print_err
 
 @undoc
 def unicode_std_stream(stream='stdout'):
     """DEPRECATED, moved to nbconvert.utils.io"""
     warn("IPython.utils.io.unicode_std_stream has moved to nbconvert.utils.io since IPython 4.0", DeprecationWarning, stacklevel=2)
     from nbconvert.utils.io import unicode_std_stream
     return unicode_std_stream(stream)

IPython/utils/openpy.py

@@ -1,105 +1,105
 """
 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)

IPython/utils/tests/test_openpy.py

@@ -1,31 +1,39
 import io
 import os.path
 import nose.tools as nt
 
 from IPython.utils import openpy
 
 mydir = os.path.dirname(__file__)
-nonascii_path = os.path.join(mydir, '../../core/tests/nonascii.py')
+nonascii_path = os.path.join(mydir, "../../core/tests/nonascii.py")
+
 
 def test_detect_encoding():
-    with open(nonascii_path, 'rb') as f:
+    with open(nonascii_path, "rb") as f:
         enc, lines = openpy.detect_encoding(f.readline)
-    nt.assert_equal(enc, 'iso-8859-5')
+    nt.assert_equal(enc, "iso-8859-5")
+
 
 def test_read_file():
-    read_specified_enc = io.open(nonascii_path, encoding='iso-8859-5').read()
+    with io.open(nonascii_path, encoding="iso-8859-5") as f:
+        read_specified_enc = f.read()
     read_detected_enc = openpy.read_py_file(nonascii_path, skip_encoding_cookie=False)
     nt.assert_equal(read_detected_enc, read_specified_enc)
-    assert u'coding: iso-8859-5' in read_detected_enc
-    
-    read_strip_enc_cookie = openpy.read_py_file(nonascii_path, skip_encoding_cookie=True)
-    assert u'coding: iso-8859-5' not in read_strip_enc_cookie
+    assert "coding: iso-8859-5" in read_detected_enc
+
+    read_strip_enc_cookie = openpy.read_py_file(
+        nonascii_path, skip_encoding_cookie=True
+    )
+    assert "coding: iso-8859-5" not in read_strip_enc_cookie
+
 
 def test_source_to_unicode():
-    with io.open(nonascii_path, 'rb') as f:
+    with io.open(nonascii_path, "rb") as f:
         source_bytes = f.read()
-    nt.assert_equal(openpy.source_to_unicode(source_bytes, skip_encoding_cookie=False).splitlines(),
-                    source_bytes.decode('iso-8859-5').splitlines())
+    nt.assert_equal(
+        openpy.source_to_unicode(source_bytes, skip_encoding_cookie=False).splitlines(),
+        source_bytes.decode("iso-8859-5").splitlines(),
+    )
 
     source_no_cookie = openpy.source_to_unicode(source_bytes, skip_encoding_cookie=True)
-    nt.assert_not_in(u'coding: iso-8859-5', source_no_cookie)
+    nt.assert_not_in("coding: iso-8859-5", source_no_cookie)