Various Python 3 fixes in IPython.utils

IPython/utils/jsonutil.py

@@ -1,161 +1,164 b''
 """Utilities to manipulate JSON objects.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING.txt, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 # stdlib
 import re
 import sys
 import types
 from datetime import datetime
 
+from IPython.utils import py3compat
+next_attr_name = '__next__' if py3compat.PY3 else 'next'
+
 #-----------------------------------------------------------------------------
 # Globals and constants
 #-----------------------------------------------------------------------------
 
 # timestamp formats
 ISO8601="%Y-%m-%dT%H:%M:%S.%f"
 ISO8601_PAT=re.compile(r"^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d+$")
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 def rekey(dikt):
     """Rekey a dict that has been forced to use str keys where there should be
     ints by json."""
     for k in dikt.iterkeys():
         if isinstance(k, basestring):
             ik=fk=None
             try:
                 ik = int(k)
             except ValueError:
                 try:
                     fk = float(k)
                 except ValueError:
                     continue
             if ik is not None:
                 nk = ik
             else:
                 nk = fk
             if nk in dikt:
                 raise KeyError("already have key %r"%nk)
             dikt[nk] = dikt.pop(k)
     return dikt
 
 
 def extract_dates(obj):
     """extract ISO8601 dates from unpacked JSON"""
     if isinstance(obj, dict):
         obj = dict(obj) # don't clobber
         for k,v in obj.iteritems():
             obj[k] = extract_dates(v)
     elif isinstance(obj, (list, tuple)):
         obj = [ extract_dates(o) for o in obj ]
     elif isinstance(obj, basestring):
         if ISO8601_PAT.match(obj):
             obj = datetime.strptime(obj, ISO8601)
     return obj
 
 def squash_dates(obj):
     """squash datetime objects into ISO8601 strings"""
     if isinstance(obj, dict):
         obj = dict(obj) # don't clobber
         for k,v in obj.iteritems():
             obj[k] = squash_dates(v)
     elif isinstance(obj, (list, tuple)):
         obj = [ squash_dates(o) for o in obj ]
     elif isinstance(obj, datetime):
         obj = obj.strftime(ISO8601)
     return obj
     
 def date_default(obj):
     """default function for packing datetime objects in JSON."""
     if isinstance(obj, datetime):
         return obj.strftime(ISO8601)
     else:
         raise TypeError("%r is not JSON serializable"%obj)
 
 
 
 def json_clean(obj):
     """Clean an object to ensure it's safe to encode in JSON.
     
     Atomic, immutable objects are returned unmodified.  Sets and tuples are
     converted to lists, lists are copied and dicts are also copied.
 
     Note: dicts whose keys could cause collisions upon encoding (such as a dict
     with both the number 1 and the string '1' as keys) will cause a ValueError
     to be raised.
 
     Parameters
     ----------
     obj : any python object
 
     Returns
     -------
     out : object
     
       A version of the input which will not cause an encoding error when
       encoded as JSON.  Note that this function does not *encode* its inputs,
       it simply sanitizes it so that there will be no encoding errors later.
 
     Examples
     --------
     >>> json_clean(4)
     4
     >>> json_clean(range(10))
     [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
     >>> json_clean(dict(x=1, y=2))
     {'y': 2, 'x': 1}
     >>> json_clean(dict(x=1, y=2, z=[1,2,3]))
     {'y': 2, 'x': 1, 'z': [1, 2, 3]}
     >>> json_clean(True)
     True
     """
     # types that are 'atomic' and ok in json as-is.  bool doesn't need to be
     # listed explicitly because bools pass as int instances
     atomic_ok = (unicode, int, float, types.NoneType)
     
     # containers that we need to convert into lists
     container_to_list = (tuple, set, types.GeneratorType)
     
     if isinstance(obj, atomic_ok):
         return obj
     
     if isinstance(obj, bytes):
         return obj.decode(sys.getdefaultencoding(), 'replace')
     
     if isinstance(obj, container_to_list) or (
-        hasattr(obj, '__iter__') and hasattr(obj, 'next')):
+        hasattr(obj, '__iter__') and hasattr(obj, next_attr_name)):
         obj = list(obj)
         
     if isinstance(obj, list):
         return [json_clean(x) for x in obj]
 
     if isinstance(obj, dict):
         # First, validate that the dict won't lose data in conversion due to
         # key collisions after stringification.  This can happen with keys like
         # True and 'true' or 1 and '1', which collide in JSON.
         nkeys = len(obj)
         nkeys_collapsed = len(set(map(str, obj)))
         if nkeys != nkeys_collapsed:
             raise ValueError('dict can not be safely converted to JSON: '
                              'key collision would lead to dropped values')
         # If all OK, proceed by making the new dict that will be json-safe
         out = {}
         for k,v in obj.iteritems():
             out[str(k)] = json_clean(v)
         return out
 
     # If we get here, we don't know how to handle the object, so we just get
     # its repr and return that.  This will catch lambdas, open sockets, class
     # objects, and any other complicated contraption that json can't encode
     return repr(obj)

IPython/utils/process.py

@@ -1,147 +1,147 b''
 # encoding: utf-8
 """
 Utilities for working with external processes.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  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
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Stdlib
 import os
 import sys
 import shlex
 
 # Our own
 if sys.platform == 'win32':
     from ._process_win32 import _find_cmd, system, getoutput, AvoidUNCPath
 else:
     from ._process_posix import _find_cmd, system, getoutput
 
 from ._process_common import getoutputerror
 from IPython.utils import py3compat
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 
 class FindCmdError(Exception):
     pass
 
 
 def find_cmd(cmd):
     """Find absolute path to executable cmd in a cross platform manner.
     
     This function tries to determine the full path to a command line program
     using `which` on Unix/Linux/OS X and `win32api` on Windows.  Most of the
     time it will use the version that is first on the users `PATH`.  If
     cmd is `python` return `sys.executable`.
 
     Warning, don't use this to find IPython command line programs as there
     is a risk you will find the wrong one.  Instead find those using the
     following code and looking for the application itself::
     
         from IPython.utils.path import get_ipython_module_path
         from IPython.utils.process import pycmd2argv
         argv = pycmd2argv(get_ipython_module_path('IPython.frontend.terminal.ipapp'))
 
     Parameters
     ----------
     cmd : str
         The command line program to look for.
     """
     if cmd == 'python':
         return os.path.abspath(sys.executable)
     try:
         path = _find_cmd(cmd).rstrip()
     except OSError:
         raise FindCmdError('command could not be found: %s' % cmd)
     # which returns empty if not found
-    if path == '':
+    if path == b'':
         raise FindCmdError('command could not be found: %s' % cmd)
     return os.path.abspath(path)
 
 
 def pycmd2argv(cmd):
     r"""Take the path of a python command and return a list (argv-style).
 
     This only works on Python based command line programs and will find the
     location of the ``python`` executable using ``sys.executable`` to make
     sure the right version is used.
 
     For a given path ``cmd``, this returns [cmd] if cmd's extension is .exe,
     .com or .bat, and [, cmd] otherwise.  
 
     Parameters
     ----------
     cmd : string
       The path of the command.
 
     Returns
     -------
     argv-style list.
     """
     ext = os.path.splitext(cmd)[1]
     if ext in ['.exe', '.com', '.bat']:
         return [cmd]
     else:
         if sys.platform == 'win32':
             # The -u option here turns on unbuffered output, which is required
             # on Win32 to prevent wierd conflict and problems with Twisted.
             # Also, use sys.executable to make sure we are picking up the 
             # right python exe.
             return [sys.executable, '-u', cmd]
         else:
             return [sys.executable, cmd]
 
 
 def arg_split(s, posix=False):
     """Split a command line's arguments in a shell-like manner.
 
     This is a modified version of the standard library's shlex.split()
     function, but with a default of posix=False for splitting, so that quotes
     in inputs are respected."""
 
     # Unfortunately, python's shlex module is buggy with unicode input:
     # http://bugs.python.org/issue1170
     # At least encoding the input when it's unicode seems to help, but there
     # may be more problems lurking.  Apparently this is fixed in python3.
     is_unicode = False
     if (not py3compat.PY3) and isinstance(s, unicode):
         is_unicode = True
         s = s.encode('utf-8')
     lex = shlex.shlex(s, posix=posix)
     lex.whitespace_split = True
     tokens = list(lex)
     if is_unicode:
         # Convert the tokens back to unicode.
         tokens = [x.decode('utf-8') for x in tokens]
     return tokens
 
 
 def abbrev_cwd():
     """ Return abbreviated version of cwd, e.g. d:mydir """
     cwd = os.getcwdu().replace('\\','/')
     drivepart = ''
     tail = cwd
     if sys.platform == 'win32':
         if len(cwd) < 4:
             return cwd
         drivepart,tail = os.path.splitdrive(cwd)
 
 
     parts = tail.split('/')
     if len(parts) > 2:
         tail = '/'.join(parts[-2:])
 
     return (drivepart + (
         cwd == '/' and '/' or tail))

IPython/utils/tests/test_path.py

@@ -1,443 +1,450 b''
 # encoding: utf-8
 """Tests for IPython.utils.path.py"""
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008  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
 #-----------------------------------------------------------------------------
 
 from __future__ import with_statement
 
 import os
 import shutil
 import sys
 import tempfile
 import StringIO
 
 from os.path import join, abspath, split
 
 import nose.tools as nt
 
 from nose import with_setup
 
 import IPython
 from IPython.testing import decorators as dec
 from IPython.testing.decorators import skip_if_not_win32, skip_win32
 from IPython.testing.tools import make_tempfile
 from IPython.utils import path, io
+from IPython.utils import py3compat
 
 # Platform-dependent imports
 try:
     import _winreg as wreg
 except ImportError:
     #Fake _winreg module on none windows platforms
-    import new
-    sys.modules["_winreg"] = new.module("_winreg")
+    import types
+    wr_name = "winreg" if py3compat.PY3 else "_winreg"
+    sys.modules[wr_name] = types.ModuleType(wr_name)
     import _winreg as wreg
     #Add entries that needs to be stubbed by the testing code
     (wreg.OpenKey, wreg.QueryValueEx,) = (None, None)
+    
+try:
+    reload
+except NameError:   # Python 3
+    from imp import reload
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 env = os.environ
 TEST_FILE_PATH = split(abspath(__file__))[0]
 TMP_TEST_DIR = tempfile.mkdtemp()
 HOME_TEST_DIR = join(TMP_TEST_DIR, "home_test_dir")
 XDG_TEST_DIR = join(HOME_TEST_DIR, "xdg_test_dir")
 IP_TEST_DIR = join(HOME_TEST_DIR,'.ipython')
 #
 # Setup/teardown functions/decorators
 #
 
 def setup():
     """Setup testenvironment for the module:
     
             - Adds dummy home dir tree
     """
     # Do not mask exceptions here.  In particular, catching WindowsError is a
     # problem because that exception is only defined on Windows...
     os.makedirs(IP_TEST_DIR)
     os.makedirs(os.path.join(XDG_TEST_DIR, 'ipython'))
 
 
 def teardown():
     """Teardown testenvironment for the module:
     
             - Remove dummy home dir tree
     """
     # Note: we remove the parent test dir, which is the root of all test
     # subdirs we may have created.  Use shutil instead of os.removedirs, so
     # that non-empty directories are all recursively removed.
     shutil.rmtree(TMP_TEST_DIR)
 
 
 def setup_environment():
     """Setup testenvironment for some functions that are tested 
     in this module. In particular this functions stores attributes
     and other things that we need to stub in some test functions.
     This needs to be done on a function level and not module level because 
     each testfunction needs a pristine environment.
     """
     global oldstuff, platformstuff
     oldstuff = (env.copy(), os.name, path.get_home_dir, IPython.__file__, os.getcwd())
 
     if os.name == 'nt':
         platformstuff = (wreg.OpenKey, wreg.QueryValueEx,)
 
 
 def teardown_environment():
     """Restore things that were remebered by the setup_environment function
     """
     (oldenv, os.name, path.get_home_dir, IPython.__file__, old_wd) = oldstuff
     os.chdir(old_wd)
     reload(path)
     
     for key in env.keys():
         if key not in oldenv:
             del env[key]
     env.update(oldenv)
     if hasattr(sys, 'frozen'):
         del sys.frozen
     if os.name == 'nt':
         (wreg.OpenKey, wreg.QueryValueEx,) = platformstuff
 
 # Build decorator that uses the setup_environment/setup_environment
 with_environment = with_setup(setup_environment, teardown_environment)
 
 
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_1():
     """Testcase for py2exe logic, un-compressed lib
     """
     sys.frozen = True
     
     #fake filename for IPython.__init__
     IPython.__file__ = abspath(join(HOME_TEST_DIR, "Lib/IPython/__init__.py"))
     
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR))
 
 
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_2():
     """Testcase for py2exe logic, compressed lib
     """
     sys.frozen = True
     #fake filename for IPython.__init__
     IPython.__file__ = abspath(join(HOME_TEST_DIR, "Library.zip/IPython/__init__.py")).lower()
     
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR).lower())
 
 
 @with_environment
 @skip_win32
 def test_get_home_dir_3():
     """Testcase $HOME is set, then use its value as home directory."""
     env["HOME"] = HOME_TEST_DIR
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, env["HOME"])
 
 
 @with_environment
 @skip_win32
 def test_get_home_dir_4():
     """Testcase $HOME is not set, os=='posix'. 
     This should fail with HomeDirError"""
     
     os.name = 'posix'
     if 'HOME' in env: del env['HOME']
     nt.assert_raises(path.HomeDirError, path.get_home_dir)
 
 
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_5():
     """Using HOMEDRIVE + HOMEPATH, os=='nt'.
 
     HOMESHARE is missing.
     """
 
     os.name = 'nt'
     env.pop('HOMESHARE', None)
     env['HOMEDRIVE'], env['HOMEPATH'] = os.path.splitdrive(HOME_TEST_DIR)
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR))
 
 
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_6():
     """Using USERPROFILE, os=='nt'.
 
     HOMESHARE, HOMEDRIVE, HOMEPATH are missing.
     """
 
     os.name = 'nt'
     env.pop('HOMESHARE', None)
     env.pop('HOMEDRIVE', None)
     env.pop('HOMEPATH', None)
     env["USERPROFILE"] = abspath(HOME_TEST_DIR)
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR))
 
 
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_7():
     """Using HOMESHARE, os=='nt'."""
 
     os.name = 'nt'
     env["HOMESHARE"] = abspath(HOME_TEST_DIR)
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR))
 
     
 # Should we stub wreg fully so we can run the test on all platforms?
 @skip_if_not_win32
 @with_environment
 def test_get_home_dir_8():
     """Using registry hack for 'My Documents', os=='nt'
     
     HOMESHARE, HOMEDRIVE, HOMEPATH, USERPROFILE and others are missing.
     """
     os.name = 'nt'
     # Remove from stub environment all keys that may be set
     for key in ['HOME', 'HOMESHARE', 'HOMEDRIVE', 'HOMEPATH', 'USERPROFILE']:
         env.pop(key, None)
 
     #Stub windows registry functions
     def OpenKey(x, y):
         class key:
             def Close(self):
                 pass
         return key()
     def QueryValueEx(x, y):
         return [abspath(HOME_TEST_DIR)]
 
     wreg.OpenKey = OpenKey
     wreg.QueryValueEx = QueryValueEx
 
     home_dir = path.get_home_dir()
     nt.assert_equal(home_dir, abspath(HOME_TEST_DIR))
 
 
 @with_environment
 def test_get_ipython_dir_1():
     """test_get_ipython_dir_1, Testcase to see if we can call get_ipython_dir without Exceptions."""
     env_ipdir = os.path.join("someplace", ".ipython")
     path._writable_dir = lambda path: True
     env['IPYTHON_DIR'] = env_ipdir
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, env_ipdir)
 
 
 @with_environment
 def test_get_ipython_dir_2():
     """test_get_ipython_dir_2, Testcase to see if we can call get_ipython_dir without Exceptions."""
     path.get_home_dir = lambda : "someplace"
     path.get_xdg_dir = lambda : None
     path._writable_dir = lambda path: True
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env.pop('XDG_CONFIG_HOME', None)
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, os.path.join("someplace", ".ipython"))
 
 @with_environment
 def test_get_ipython_dir_3():
     """test_get_ipython_dir_3, use XDG if defined, and .ipython doesn't exist."""
     path.get_home_dir = lambda : "someplace"
     path._writable_dir = lambda path: True
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env['XDG_CONFIG_HOME'] = XDG_TEST_DIR
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, os.path.join(XDG_TEST_DIR, "ipython"))
 
 @with_environment
 def test_get_ipython_dir_4():
     """test_get_ipython_dir_4, use XDG if both exist."""
     path.get_home_dir = lambda : HOME_TEST_DIR
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env['XDG_CONFIG_HOME'] = XDG_TEST_DIR
     xdg_ipdir = os.path.join(XDG_TEST_DIR, "ipython")
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, xdg_ipdir)
 
 @with_environment
 def test_get_ipython_dir_5():
     """test_get_ipython_dir_5, use .ipython if exists and XDG defined, but doesn't exist."""
     path.get_home_dir = lambda : HOME_TEST_DIR
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env['XDG_CONFIG_HOME'] = XDG_TEST_DIR
     os.rmdir(os.path.join(XDG_TEST_DIR, 'ipython'))
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, IP_TEST_DIR)
 
 @with_environment
 def test_get_ipython_dir_6():
     """test_get_ipython_dir_6, use XDG if defined and neither exist."""
     xdg = os.path.join(HOME_TEST_DIR, 'somexdg')
     os.mkdir(xdg)
     shutil.rmtree(os.path.join(HOME_TEST_DIR, '.ipython'))
     path.get_home_dir = lambda : HOME_TEST_DIR
     path.get_xdg_dir = lambda : xdg
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env.pop('XDG_CONFIG_HOME', None)
     xdg_ipdir = os.path.join(xdg, "ipython")
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, xdg_ipdir)
 
 @with_environment
 def test_get_ipython_dir_7():
     """test_get_ipython_dir_7, test home directory expansion on IPYTHON_DIR"""
     path._writable_dir = lambda path: True
     home_dir = os.path.expanduser('~')
     env['IPYTHON_DIR'] = os.path.join('~', 'somewhere')
     ipdir = path.get_ipython_dir()
     nt.assert_equal(ipdir, os.path.join(home_dir, 'somewhere'))
 
 
 @with_environment
 def test_get_xdg_dir_1():
     """test_get_xdg_dir_1, check xdg_dir"""
     reload(path)
     path._writable_dir = lambda path: True
     path.get_home_dir = lambda : 'somewhere'
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env.pop('XDG_CONFIG_HOME', None)
     
     nt.assert_equal(path.get_xdg_dir(), os.path.join('somewhere', '.config'))
 
 
 @with_environment
 def test_get_xdg_dir_1():
     """test_get_xdg_dir_1, check nonexistant xdg_dir"""
     reload(path)
     path.get_home_dir = lambda : HOME_TEST_DIR
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env.pop('XDG_CONFIG_HOME', None)
     nt.assert_equal(path.get_xdg_dir(), None)
 
 @with_environment
 def test_get_xdg_dir_2():
     """test_get_xdg_dir_2, check xdg_dir default to ~/.config"""
     reload(path)
     path.get_home_dir = lambda : HOME_TEST_DIR
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env.pop('XDG_CONFIG_HOME', None)
     cfgdir=os.path.join(path.get_home_dir(), '.config')
     os.makedirs(cfgdir)
     
     nt.assert_equal(path.get_xdg_dir(), cfgdir)
 
 def test_filefind():
     """Various tests for filefind"""
     f = tempfile.NamedTemporaryFile()
     # print 'fname:',f.name
     alt_dirs = path.get_ipython_dir()
     t = path.filefind(f.name, alt_dirs)
     # print 'found:',t
 
 
 def test_get_ipython_package_dir():
     ipdir = path.get_ipython_package_dir()
     nt.assert_true(os.path.isdir(ipdir))
 
 
 def test_get_ipython_module_path():
     ipapp_path = path.get_ipython_module_path('IPython.frontend.terminal.ipapp')
     nt.assert_true(os.path.isfile(ipapp_path))
 
 
 @dec.skip_if_not_win32
 def test_get_long_path_name_win32():
     p = path.get_long_path_name('c:\\docume~1')
     nt.assert_equals(p,u'c:\\Documents and Settings') 
 
 
 @dec.skip_win32
 def test_get_long_path_name():
     p = path.get_long_path_name('/usr/local')
     nt.assert_equals(p,'/usr/local')
 
 @dec.skip_win32 # can't create not-user-writable dir on win
 @with_environment
 def test_not_writable_ipdir():
     tmpdir = tempfile.mkdtemp()
     os.name = "posix"
     env.pop('IPYTHON_DIR', None)
     env.pop('IPYTHONDIR', None)
     env.pop('XDG_CONFIG_HOME', None)
     env['HOME'] = tmpdir
     ipdir = os.path.join(tmpdir, '.ipython')
     os.mkdir(ipdir)
     os.chmod(ipdir, 600)
     stderr = io.stderr
     pipe = StringIO.StringIO()
     io.stderr = pipe
     ipdir = path.get_ipython_dir()
     io.stderr.flush()
     io.stderr = stderr
     nt.assert_true('WARNING' in pipe.getvalue())
     env.pop('IPYTHON_DIR', None)
 
 def test_unquote_filename():
     for win32 in (True, False):
         nt.assert_equals(path.unquote_filename('foo.py', win32=win32), 'foo.py')
         nt.assert_equals(path.unquote_filename('foo bar.py', win32=win32), 'foo bar.py')
     nt.assert_equals(path.unquote_filename('"foo.py"', win32=True), 'foo.py')
     nt.assert_equals(path.unquote_filename('"foo bar.py"', win32=True), 'foo bar.py')
     nt.assert_equals(path.unquote_filename("'foo.py'", win32=True), 'foo.py')
     nt.assert_equals(path.unquote_filename("'foo bar.py'", win32=True), 'foo bar.py')
     nt.assert_equals(path.unquote_filename('"foo.py"', win32=False), '"foo.py"')
     nt.assert_equals(path.unquote_filename('"foo bar.py"', win32=False), '"foo bar.py"')
     nt.assert_equals(path.unquote_filename("'foo.py'", win32=False), "'foo.py'")
     nt.assert_equals(path.unquote_filename("'foo bar.py'", win32=False), "'foo bar.py'")
 
 @with_environment
 def test_get_py_filename():
     os.chdir(TMP_TEST_DIR)
     for win32 in (True, False):
         with make_tempfile('foo.py'):
             nt.assert_equals(path.get_py_filename('foo.py', force_win32=win32), 'foo.py')
             nt.assert_equals(path.get_py_filename('foo', force_win32=win32), 'foo.py')
         with make_tempfile('foo'):
             nt.assert_equals(path.get_py_filename('foo', force_win32=win32), 'foo')
             nt.assert_raises(IOError, path.get_py_filename, 'foo.py', force_win32=win32)
         nt.assert_raises(IOError, path.get_py_filename, 'foo', force_win32=win32)
         nt.assert_raises(IOError, path.get_py_filename, 'foo.py', force_win32=win32)
         true_fn = 'foo with spaces.py'
         with make_tempfile(true_fn):
             nt.assert_equals(path.get_py_filename('foo with spaces', force_win32=win32), true_fn)
             nt.assert_equals(path.get_py_filename('foo with spaces.py', force_win32=win32), true_fn)
             if win32:
                 nt.assert_equals(path.get_py_filename('"foo with spaces.py"', force_win32=True), true_fn)
                 nt.assert_equals(path.get_py_filename("'foo with spaces.py'", force_win32=True), true_fn)
             else:
                 nt.assert_raises(IOError, path.get_py_filename, '"foo with spaces.py"', force_win32=False)
                 nt.assert_raises(IOError, path.get_py_filename, "'foo with spaces.py'", force_win32=False)

IPython/utils/tests/test_process.py

@@ -1,98 +1,98 b''
 # encoding: utf-8
 """
 Tests for platutils.py
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  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 sys
 from unittest import TestCase
 
 import nose.tools as nt
 
 from IPython.utils.process import (find_cmd, FindCmdError, arg_split,
                                    system, getoutput, getoutputerror)
 from IPython.testing import decorators as dec
 from IPython.testing import tools as tt
 
 #-----------------------------------------------------------------------------
 # Tests
 #-----------------------------------------------------------------------------
 
 def test_find_cmd_python():
     """Make sure we find sys.exectable for python."""
     nt.assert_equals(find_cmd('python'), sys.executable)
 
     
 @dec.skip_win32
 def test_find_cmd_ls():
     """Make sure we can find the full path to ls."""
     path = find_cmd('ls')
-    nt.assert_true(path.endswith('ls'))
+    nt.assert_true(path.endswith(b'ls'))
 
     
 def has_pywin32():
     try:
         import win32api
     except ImportError:
         return False
     return True
 
 
 @dec.onlyif(has_pywin32, "This test requires win32api to run")
 def test_find_cmd_pythonw():
     """Try to find pythonw on Windows."""
     path = find_cmd('pythonw')
     nt.assert_true(path.endswith('pythonw.exe'))
 
 
 @dec.onlyif(lambda : sys.platform != 'win32' or has_pywin32(),
             "This test runs on posix or in win32 with win32api installed")
 def test_find_cmd_fail():
     """Make sure that FindCmdError is raised if we can't find the cmd."""
     nt.assert_raises(FindCmdError,find_cmd,'asdfasdf')
 
     
 def test_arg_split():
     """Ensure that argument lines are correctly split like in a shell."""
     tests = [['hi', ['hi']],
              [u'hi', [u'hi']],
              ['hello there', ['hello', 'there']],
              [u'h\N{LATIN SMALL LETTER A WITH CARON}llo', [u'h\N{LATIN SMALL LETTER A WITH CARON}llo']],
              ['something "with quotes"', ['something', '"with quotes"']],
              ]
     for argstr, argv in tests:
         nt.assert_equal(arg_split(argstr), argv)
 
 
 class SubProcessTestCase(TestCase, tt.TempFileMixin):
     def setUp(self):
         """Make a valid python temp file."""
         lines = ["from __future__ import print_function",
                  "import sys",
                  "print('on stdout', end='', file=sys.stdout)",
                  "print('on stderr', end='', file=sys.stderr)",
                  "sys.stdout.flush()",
                  "sys.stderr.flush()"]
         self.mktmp('\n'.join(lines))
 
     def test_system(self):
         system('python "%s"' % self.fname)
 
     def test_getoutput(self):
         out = getoutput('python "%s"' % self.fname)
         self.assertEquals(out, 'on stdout')
 
     def test_getoutput(self):
         out, err = getoutputerror('python "%s"' % self.fname)
         self.assertEquals(out, 'on stdout')
         self.assertEquals(err, 'on stderr')

IPython/utils/text.py

@@ -1,715 +1,715 b''
 # encoding: utf-8
 """
 Utilities for working with strings and text.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  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 __main__
 
 import os
 import re
 import shutil
 import textwrap
 from string import Formatter
 
 from IPython.external.path import path
 from IPython.utils import py3compat
 from IPython.utils.io import nlprint
 from IPython.utils.data import flatten
 
 #-----------------------------------------------------------------------------
 # Code
 #-----------------------------------------------------------------------------
 
 
 def unquote_ends(istr):
     """Remove a single pair of quotes from the endpoints of a string."""
 
     if not istr:
         return istr
     if (istr[0]=="'" and istr[-1]=="'") or \
        (istr[0]=='"' and istr[-1]=='"'):
         return istr[1:-1]
     else:
         return istr
 
 
 class LSString(str):
     """String derivative with a special access attributes.
 
     These are normal strings, but with the special attributes:
 
         .l (or .list) : value as list (split on newlines).
         .n (or .nlstr): original value (the string itself).
         .s (or .spstr): value as whitespace-separated string.
         .p (or .paths): list of path objects
 
     Any values which require transformations are computed only once and
     cached.
 
     Such strings are very useful to efficiently interact with the shell, which
     typically only understands whitespace-separated options for commands."""
 
     def get_list(self):
         try:
             return self.__list
         except AttributeError:
             self.__list = self.split('\n')
             return self.__list
 
     l = list = property(get_list)
 
     def get_spstr(self):
         try:
             return self.__spstr
         except AttributeError:
             self.__spstr = self.replace('\n',' ')
             return self.__spstr
 
     s = spstr = property(get_spstr)
 
     def get_nlstr(self):
         return self
 
     n = nlstr = property(get_nlstr)
 
     def get_paths(self):
         try:
             return self.__paths
         except AttributeError:
             self.__paths = [path(p) for p in self.split('\n') if os.path.exists(p)]
             return self.__paths
 
     p = paths = property(get_paths)
 
 # FIXME: We need to reimplement type specific displayhook and then add this
 # back as a custom printer. This should also be moved outside utils into the
 # core.
 
 # def print_lsstring(arg):
 #     """ Prettier (non-repr-like) and more informative printer for LSString """
 #     print "LSString (.p, .n, .l, .s available). Value:"
 #     print arg
 # 
 # 
 # print_lsstring = result_display.when_type(LSString)(print_lsstring)
 
 
 class SList(list):
     """List derivative with a special access attributes.
 
     These are normal lists, but with the special attributes:
 
         .l (or .list) : value as list (the list itself).
         .n (or .nlstr): value as a string, joined on newlines.
         .s (or .spstr): value as a string, joined on spaces.
         .p (or .paths): list of path objects
 
     Any values which require transformations are computed only once and
     cached."""
 
     def get_list(self):
         return self
 
     l = list = property(get_list)
 
     def get_spstr(self):
         try:
             return self.__spstr
         except AttributeError:
             self.__spstr = ' '.join(self)
             return self.__spstr
 
     s = spstr = property(get_spstr)
 
     def get_nlstr(self):
         try:
             return self.__nlstr
         except AttributeError:
             self.__nlstr = '\n'.join(self)
             return self.__nlstr
 
     n = nlstr = property(get_nlstr)
 
     def get_paths(self):
         try:
             return self.__paths
         except AttributeError:
             self.__paths = [path(p) for p in self if os.path.exists(p)]
             return self.__paths
 
     p = paths = property(get_paths)
 
     def grep(self, pattern, prune = False, field = None):
         """ Return all strings matching 'pattern' (a regex or callable)
 
         This is case-insensitive. If prune is true, return all items
         NOT matching the pattern.
 
         If field is specified, the match must occur in the specified
         whitespace-separated field.
 
         Examples::
 
             a.grep( lambda x: x.startswith('C') )
             a.grep('Cha.*log', prune=1)
             a.grep('chm', field=-1)
         """
 
         def match_target(s):
             if field is None:
                 return s
             parts = s.split()
             try:
                 tgt = parts[field]
                 return tgt
             except IndexError:
                 return ""
 
         if isinstance(pattern, basestring):
             pred = lambda x : re.search(pattern, x, re.IGNORECASE)
         else:
             pred = pattern
         if not prune:
             return SList([el for el in self if pred(match_target(el))])
         else:
             return SList([el for el in self if not pred(match_target(el))])
 
     def fields(self, *fields):
         """ Collect whitespace-separated fields from string list
 
         Allows quick awk-like usage of string lists.
 
         Example data (in var a, created by 'a = !ls -l')::
             -rwxrwxrwx  1 ville None      18 Dec 14  2006 ChangeLog
             drwxrwxrwx+ 6 ville None       0 Oct 24 18:05 IPython
 
         a.fields(0) is ['-rwxrwxrwx', 'drwxrwxrwx+']
         a.fields(1,0) is ['1 -rwxrwxrwx', '6 drwxrwxrwx+']
         (note the joining by space).
         a.fields(-1) is ['ChangeLog', 'IPython']
 
         IndexErrors are ignored.
 
         Without args, fields() just split()'s the strings.
         """
         if len(fields) == 0:
             return [el.split() for el in self]
 
         res = SList()
         for el in [f.split() for f in self]:
             lineparts = []
 
             for fd in fields:
                 try:
                     lineparts.append(el[fd])
                 except IndexError:
                     pass
             if lineparts:
                 res.append(" ".join(lineparts))
 
         return res
 
     def sort(self,field= None,  nums = False):
         """ sort by specified fields (see fields())
 
         Example::
             a.sort(1, nums = True)
 
         Sorts a by second field, in numerical order (so that 21 > 3)
 
         """
 
         #decorate, sort, undecorate
         if field is not None:
             dsu = [[SList([line]).fields(field),  line] for line in self]
         else:
             dsu = [[line,  line] for line in self]
         if nums:
             for i in range(len(dsu)):
                 numstr = "".join([ch for ch in dsu[i][0] if ch.isdigit()])
                 try:
                     n = int(numstr)
                 except ValueError:
                     n = 0;
                 dsu[i][0] = n
 
 
         dsu.sort()
         return SList([t[1] for t in dsu])
 
 
 # FIXME: We need to reimplement type specific displayhook and then add this
 # back as a custom printer. This should also be moved outside utils into the
 # core.
 
 # def print_slist(arg):
 #     """ Prettier (non-repr-like) and more informative printer for SList """
 #     print "SList (.p, .n, .l, .s, .grep(), .fields(), sort() available):"
 #     if hasattr(arg,  'hideonce') and arg.hideonce:
 #         arg.hideonce = False
 #         return
 # 
 #     nlprint(arg)
 # 
 # print_slist = result_display.when_type(SList)(print_slist)
 
 
 def esc_quotes(strng):
     """Return the input string with single and double quotes escaped out"""
 
     return strng.replace('"','\\"').replace("'","\\'")
 
 
 def make_quoted_expr(s):
     """Return string s in appropriate quotes, using raw string if possible.
 
     XXX - example removed because it caused encoding errors in documentation
     generation.  We need a new example that doesn't contain invalid chars.
 
     Note the use of raw string and padding at the end to allow trailing
     backslash.
     """
 
     tail = ''
     tailpadding = ''
     raw  = ''
     ucode = '' if py3compat.PY3 else 'u'
     if "\\" in s:
         raw = 'r'
         if s.endswith('\\'):
             tail = '[:-1]'
             tailpadding = '_'
     if '"' not in s:
         quote = '"'
     elif "'" not in s:
         quote = "'"
     elif '"""' not in s and not s.endswith('"'):
         quote = '"""'
     elif "'''" not in s and not s.endswith("'"):
         quote = "'''"
     else:
         # give up, backslash-escaped string will do
         return '"%s"' % esc_quotes(s)
     res = ucode + raw + quote + s + tailpadding + quote + tail
     return res
 
 
 def qw(words,flat=0,sep=None,maxsplit=-1):
     """Similar to Perl's qw() operator, but with some more options.
 
     qw(words,flat=0,sep=' ',maxsplit=-1) -> words.split(sep,maxsplit)
 
     words can also be a list itself, and with flat=1, the output will be
     recursively flattened.
 
     Examples:
 
     >>> qw('1 2')
     ['1', '2']
 
     >>> qw(['a b','1 2',['m n','p q']])
     [['a', 'b'], ['1', '2'], [['m', 'n'], ['p', 'q']]]
 
     >>> qw(['a b','1 2',['m n','p q']],flat=1)
     ['a', 'b', '1', '2', 'm', 'n', 'p', 'q']
     """
 
     if isinstance(words, basestring):
         return [word.strip() for word in words.split(sep,maxsplit)
                 if word and not word.isspace() ]
     if flat:
         return flatten(map(qw,words,[1]*len(words)))
     return map(qw,words)
 
 
 def qwflat(words,sep=None,maxsplit=-1):
     """Calls qw(words) in flat mode. It's just a convenient shorthand."""
     return qw(words,1,sep,maxsplit)
 
 
 def qw_lol(indata):
     """qw_lol('a b') -> [['a','b']],
     otherwise it's just a call to qw().
 
     We need this to make sure the modules_some keys *always* end up as a
     list of lists."""
 
     if isinstance(indata, basestring):
         return [qw(indata)]
     else:
         return qw(indata)
 
 
 def grep(pat,list,case=1):
     """Simple minded grep-like function.
     grep(pat,list) returns occurrences of pat in list, None on failure.
 
     It only does simple string matching, with no support for regexps. Use the
     option case=0 for case-insensitive matching."""
 
     # This is pretty crude. At least it should implement copying only references
     # to the original data in case it's big. Now it copies the data for output.
     out=[]
     if case:
         for term in list:
             if term.find(pat)>-1: out.append(term)
     else:
         lpat=pat.lower()
         for term in list:
             if term.lower().find(lpat)>-1: out.append(term)
 
     if len(out): return out
     else: return None
 
 
 def dgrep(pat,*opts):
     """Return grep() on dir()+dir(__builtins__).
 
     A very common use of grep() when working interactively."""
 
     return grep(pat,dir(__main__)+dir(__main__.__builtins__),*opts)
 
 
 def idgrep(pat):
     """Case-insensitive dgrep()"""
 
     return dgrep(pat,0)
 
 
 def igrep(pat,list):
     """Synonym for case-insensitive grep."""
 
     return grep(pat,list,case=0)
 
 
 def indent(instr,nspaces=4, ntabs=0, flatten=False):
     """Indent a string a given number of spaces or tabstops.
 
     indent(str,nspaces=4,ntabs=0) -> indent str by ntabs+nspaces.
     
     Parameters
     ----------
     
     instr : basestring
         The string to be indented.
     nspaces : int (default: 4)
         The number of spaces to be indented.
     ntabs : int (default: 0)
         The number of tabs to be indented.
     flatten : bool (default: False)
         Whether to scrub existing indentation.  If True, all lines will be
         aligned to the same indentation.  If False, existing indentation will
         be strictly increased.
     
     Returns
     -------
     
     str|unicode : string indented by ntabs and nspaces.
     
     """
     if instr is None:
         return
     ind = '\t'*ntabs+' '*nspaces
     if flatten:
         pat = re.compile(r'^\s*', re.MULTILINE)
     else:
         pat = re.compile(r'^', re.MULTILINE)
     outstr = re.sub(pat, ind, instr)
     if outstr.endswith(os.linesep+ind):
         return outstr[:-len(ind)]
     else:
         return outstr
 
 def native_line_ends(filename,backup=1):
     """Convert (in-place) a file to line-ends native to the current OS.
 
     If the optional backup argument is given as false, no backup of the
     original file is left.  """
 
     backup_suffixes = {'posix':'~','dos':'.bak','nt':'.bak','mac':'.bak'}
 
     bak_filename = filename + backup_suffixes[os.name]
 
     original = open(filename).read()
     shutil.copy2(filename,bak_filename)
     try:
         new = open(filename,'wb')
         new.write(os.linesep.join(original.splitlines()))
         new.write(os.linesep) # ALWAYS put an eol at the end of the file
         new.close()
     except:
         os.rename(bak_filename,filename)
     if not backup:
         try:
             os.remove(bak_filename)
         except:
             pass
 
 
 def list_strings(arg):
     """Always return a list of strings, given a string or list of strings
     as input.
 
     :Examples:
 
         In [7]: list_strings('A single string')
         Out[7]: ['A single string']
 
         In [8]: list_strings(['A single string in a list'])
         Out[8]: ['A single string in a list']
 
         In [9]: list_strings(['A','list','of','strings'])
         Out[9]: ['A', 'list', 'of', 'strings']
     """
 
     if isinstance(arg,basestring): return [arg]
     else: return arg
 
 
 def marquee(txt='',width=78,mark='*'):
     """Return the input string centered in a 'marquee'.
 
     :Examples:
 
         In [16]: marquee('A test',40)
         Out[16]: '**************** A test ****************'
 
         In [17]: marquee('A test',40,'-')
         Out[17]: '---------------- A test ----------------'
 
         In [18]: marquee('A test',40,' ')
         Out[18]: '                 A test                 '
 
     """
     if not txt:
         return (mark*width)[:width]
     nmark = (width-len(txt)-2)//len(mark)//2
     if nmark < 0: nmark =0
     marks = mark*nmark
     return '%s %s %s' % (marks,txt,marks)
 
 
 ini_spaces_re = re.compile(r'^(\s+)')
 
 def num_ini_spaces(strng):
     """Return the number of initial spaces in a string"""
 
     ini_spaces = ini_spaces_re.match(strng)
     if ini_spaces:
         return ini_spaces.end()
     else:
         return 0
 
 
 def format_screen(strng):
     """Format a string for screen printing.
 
     This removes some latex-type format codes."""
     # Paragraph continue
     par_re = re.compile(r'\\$',re.MULTILINE)
     strng = par_re.sub('',strng)
     return strng
 
 def dedent(text):
     """Equivalent of textwrap.dedent that ignores unindented first line.
     
     This means it will still dedent strings like:
     '''foo
     is a bar
     '''
     
     For use in wrap_paragraphs.
     """
     
     if text.startswith('\n'):
         # text starts with blank line, don't ignore the first line
         return textwrap.dedent(text)
     
     # split first line
     splits = text.split('\n',1)
     if len(splits) == 1:
         # only one line
         return textwrap.dedent(text)
     
     first, rest = splits
     # dedent everything but the first line
     rest = textwrap.dedent(rest)
     return '\n'.join([first, rest])
 
 def wrap_paragraphs(text, ncols=80):
     """Wrap multiple paragraphs to fit a specified width.
     
     This is equivalent to textwrap.wrap, but with support for multiple
     paragraphs, as separated by empty lines.
     
     Returns
     -------
     
     list of complete paragraphs, wrapped to fill `ncols` columns.
     """
     paragraph_re = re.compile(r'\n(\s*\n)+', re.MULTILINE)
     text = dedent(text).strip()
     paragraphs = paragraph_re.split(text)[::2] # every other entry is space
     out_ps = []
     indent_re = re.compile(r'\n\s+', re.MULTILINE)
     for p in paragraphs:
         # presume indentation that survives dedent is meaningful formatting, 
         # so don't fill unless text is flush.
         if indent_re.search(p) is None:
             # wrap paragraph
             p = textwrap.fill(p, ncols)
         out_ps.append(p)
     return out_ps
     
 
 
 class EvalFormatter(Formatter):
     """A String Formatter that allows evaluation of simple expressions.
     
     Any time a format key is not found in the kwargs,
     it will be tried as an expression in the kwargs namespace.
     
     This is to be used in templating cases, such as the parallel batch
     script templates, where simple arithmetic on arguments is useful.
     
     Examples
     --------
     
     In [1]: f = EvalFormatter()
-    In [2]: f.format('{n/4}', n=8)
+    In [2]: f.format('{n//4}', n=8)
     Out[2]: '2'
     
-    In [3]: f.format('{range(3)}')
+    In [3]: f.format('{list(range(3))}')
     Out[3]: '[0, 1, 2]'
 
     In [4]: f.format('{3*2}')
     Out[4]: '6'
     """
     
     # should we allow slicing by disabling the format_spec feature?
     allow_slicing = True
     
     # copied from Formatter._vformat with minor changes to allow eval
     # and replace the format_spec code with slicing
     def _vformat(self, format_string, args, kwargs, used_args, recursion_depth):
         if recursion_depth < 0:
             raise ValueError('Max string recursion exceeded')
         result = []
         for literal_text, field_name, format_spec, conversion in \
                 self.parse(format_string):
 
             # output the literal text
             if literal_text:
                 result.append(literal_text)
 
             # if there's a field, output it
             if field_name is not None:
                 # this is some markup, find the object and do
                 #  the formatting
 
                 if self.allow_slicing and format_spec:
                     # override format spec, to allow slicing:
                     field_name = ':'.join([field_name, format_spec])
                     format_spec = ''
 
                 # eval the contents of the field for the object
                 # to be formatted
                 obj = eval(field_name, kwargs)
 
                 # do any conversion on the resulting object
                 obj = self.convert_field(obj, conversion)
 
                 # expand the format spec, if needed
                 format_spec = self._vformat(format_spec, args, kwargs,
                                             used_args, recursion_depth-1)
 
                 # format the object and append to the result
                 result.append(self.format_field(obj, format_spec))
 
         return ''.join(result)
 
 
 def columnize(items, separator='  ', displaywidth=80):
     """ Transform a list of strings into a single string with columns.
 
     Parameters
     ----------
     items : sequence of strings
         The strings to process.
 
     separator : str, optional [default is two spaces]
         The string that separates columns.
 
     displaywidth : int, optional [default is 80]
         Width of the display in number of characters.
     
     Returns
     -------
     The formatted string.
     """
     # Note: this code is adapted from columnize 0.3.2.
     # See http://code.google.com/p/pycolumnize/
 
     # Some degenerate cases.
     size = len(items)
     if size == 0: 
         return '\n'
     elif size == 1:
         return '%s\n' % items[0]
 
     # Special case: if any item is longer than the maximum width, there's no
     # point in triggering the logic below...
     item_len = map(len, items) # save these, we can reuse them below
     longest = max(item_len)
     if longest >= displaywidth:
         return '\n'.join(items+[''])
 
     # Try every row count from 1 upwards
     array_index = lambda nrows, row, col: nrows*col + row
     for nrows in range(1, size):
         ncols = (size + nrows - 1) // nrows
         colwidths = []
         totwidth = -len(separator)
         for col in range(ncols):
             # Get max column width for this column
             colwidth = 0
             for row in range(nrows):
                 i = array_index(nrows, row, col)
                 if i >= size: break
                 x, len_x = items[i], item_len[i]
                 colwidth = max(colwidth, len_x)
             colwidths.append(colwidth)
             totwidth += colwidth + len(separator)
             if totwidth > displaywidth: 
                 break
         if totwidth <= displaywidth: 
             break
 
     # The smallest number of rows computed and the max widths for each
     # column has been obtained. Now we just have to format each of the rows.
     string = ''
     for row in range(nrows):
         texts = []
         for col in range(ncols):
             i = row + nrows*col
             if i >= size:
                 texts.append('')
             else:
                 texts.append(items[i])
         while texts and not texts[-1]:
             del texts[-1]
         for col in range(len(texts)):
             texts[col] = texts[col].ljust(colwidths[col])
         string += '%s\n' % separator.join(texts)
     return string

IPython/utils/traitlets.py

@@ -1,1392 +1,1394 b''
 # encoding: utf-8
 """
 A lightweight Traits like module.
 
 This is designed to provide a lightweight, simple, pure Python version of
 many of the capabilities of enthought.traits.  This includes:
 
 * Validation
 * Type specification with defaults
 * Static and dynamic notification
 * Basic predefined types
 * An API that is similar to enthought.traits
 
 We don't support:
 
 * Delegation
 * Automatic GUI generation
 * A full set of trait types.  Most importantly, we don't provide container
   traits (list, dict, tuple) that can trigger notifications if their
   contents change.
 * API compatibility with enthought.traits
 
 There are also some important difference in our design:
 
 * enthought.traits does not validate default values.  We do.
 
 We choose to create this module because we need these capabilities, but
 we need them to be pure Python so they work in all Python implementations,
 including Jython and IronPython.
 
 Authors:
 
 * Brian Granger
 * Enthought, Inc.  Some of the code in this file comes from enthought.traits
   and is licensed under the BSD license.  Also, many of the ideas also come
   from enthought.traits even though our implementation is very different.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  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 inspect
 import re
 import sys
 import types
 from types import FunctionType
 try:
     from types import ClassType, InstanceType
     ClassTypes = (ClassType, type)
 except:
     ClassTypes = (type,)
     
 from .importstring import import_item
 from IPython.utils import py3compat
 
 SequenceTypes = (list, tuple, set, frozenset)
 
 #-----------------------------------------------------------------------------
 # Basic classes
 #-----------------------------------------------------------------------------
 
 
 class NoDefaultSpecified ( object ): pass
 NoDefaultSpecified = NoDefaultSpecified()
 
 
 class Undefined ( object ): pass
 Undefined = Undefined()
 
 class TraitError(Exception):
     pass
 
 #-----------------------------------------------------------------------------
 # Utilities
 #-----------------------------------------------------------------------------
 
 
 def class_of ( object ):
     """ Returns a string containing the class name of an object with the
     correct indefinite article ('a' or 'an') preceding it (e.g., 'an Image',
     'a PlotValue').
     """
     if isinstance( object, basestring ):
         return add_article( object )
 
     return add_article( object.__class__.__name__ )
 
 
 def add_article ( name ):
     """ Returns a string containing the correct indefinite article ('a' or 'an')
     prefixed to the specified string.
     """
     if name[:1].lower() in 'aeiou':
        return 'an ' + name
 
     return 'a ' + name
 
 
 def repr_type(obj):
     """ Return a string representation of a value and its type for readable
     error messages.
     """
     the_type = type(obj)
     if (not py3compat.PY3) and the_type is InstanceType:
         # Old-style class.
         the_type = obj.__class__
     msg = '%r %r' % (obj, the_type)
     return msg
 
 
 def parse_notifier_name(name):
     """Convert the name argument to a list of names.
     
     Examples
     --------
     
     >>> parse_notifier_name('a')
     ['a']
     >>> parse_notifier_name(['a','b'])
     ['a', 'b']
     >>> parse_notifier_name(None)
     ['anytrait']
     """
     if isinstance(name, str):
         return [name]
     elif name is None:
         return ['anytrait']
     elif isinstance(name, (list, tuple)):
         for n in name:
             assert isinstance(n, str), "names must be strings"
         return name
 
 
 class _SimpleTest:
     def __init__ ( self, value ): self.value = value
     def __call__ ( self, test  ):
         return test == self.value
     def __repr__(self):
         return "<SimpleTest(%r)" % self.value
     def __str__(self):
         return self.__repr__()
 
 
 def getmembers(object, predicate=None):
     """A safe version of inspect.getmembers that handles missing attributes.
 
     This is useful when there are descriptor based attributes that for 
     some reason raise AttributeError even though they exist.  This happens
     in zope.inteface with the __provides__ attribute.
     """
     results = []
     for key in dir(object):
         try:
             value = getattr(object, key)
         except AttributeError:
             pass
         else:
             if not predicate or predicate(value):
                 results.append((key, value))
     results.sort()
     return results
 
 
 #-----------------------------------------------------------------------------
 # Base TraitType for all traits
 #-----------------------------------------------------------------------------
 
 
 class TraitType(object):
     """A base class for all trait descriptors.
 
     Notes
     -----
     Our implementation of traits is based on Python's descriptor
     prototol.  This class is the base class for all such descriptors.  The
     only magic we use is a custom metaclass for the main :class:`HasTraits`
     class that does the following:
 
     1. Sets the :attr:`name` attribute of every :class:`TraitType`
        instance in the class dict to the name of the attribute.
     2. Sets the :attr:`this_class` attribute of every :class:`TraitType`
        instance in the class dict to the *class* that declared the trait.
        This is used by the :class:`This` trait to allow subclasses to
        accept superclasses for :class:`This` values.
     """
     
 
     metadata = {}
     default_value = Undefined
     info_text = 'any value'
 
     def __init__(self, default_value=NoDefaultSpecified, **metadata):
         """Create a TraitType.
         """
         if default_value is not NoDefaultSpecified:
             self.default_value = default_value
 
         if len(metadata) > 0:
             if len(self.metadata) > 0:
                 self._metadata = self.metadata.copy()
                 self._metadata.update(metadata)
             else:
                 self._metadata = metadata
         else:
             self._metadata = self.metadata
 
         self.init()
 
     def init(self):
         pass
 
     def get_default_value(self):
         """Create a new instance of the default value."""
         return self.default_value
 
     def instance_init(self, obj):
         """This is called by :meth:`HasTraits.__new__` to finish init'ing.
 
         Some stages of initialization must be delayed until the parent
         :class:`HasTraits` instance has been created.  This method is
         called in :meth:`HasTraits.__new__` after the instance has been
         created.
 
         This method trigger the creation and validation of default values
         and also things like the resolution of str given class names in 
         :class:`Type` and :class`Instance`.
 
         Parameters
         ----------
         obj : :class:`HasTraits` instance
             The parent :class:`HasTraits` instance that has just been
             created.
         """
         self.set_default_value(obj)
 
     def set_default_value(self, obj):
         """Set the default value on a per instance basis.
 
         This method is called by :meth:`instance_init` to create and
         validate the default value.  The creation and validation of 
         default values must be delayed until the parent :class:`HasTraits`
         class has been instantiated.
         """
         # Check for a deferred initializer defined in the same class as the
         # trait declaration or above.
         mro = type(obj).mro()
         meth_name = '_%s_default' % self.name
         for cls in mro[:mro.index(self.this_class)+1]:
             if meth_name in cls.__dict__:
                 break
         else:
             # We didn't find one. Do static initialization.
             dv = self.get_default_value()
             newdv = self._validate(obj, dv)
             obj._trait_values[self.name] = newdv
             return
         # Complete the dynamic initialization.
         obj._trait_dyn_inits[self.name] = cls.__dict__[meth_name]
 
     def __get__(self, obj, cls=None):
         """Get the value of the trait by self.name for the instance.
 
         Default values are instantiated when :meth:`HasTraits.__new__`
         is called.  Thus by the time this method gets called either the 
         default value or a user defined value (they called :meth:`__set__`)
         is in the :class:`HasTraits` instance.
         """
         if obj is None:
             return self
         else:
             try:
                 value = obj._trait_values[self.name]
             except KeyError:
                 # Check for a dynamic initializer.
                 if self.name in obj._trait_dyn_inits:
                     value = obj._trait_dyn_inits[self.name](obj)
                     # FIXME: Do we really validate here?
                     value = self._validate(obj, value)
                     obj._trait_values[self.name] = value
                     return value
                 else:
                     raise TraitError('Unexpected error in TraitType: '
                         'both default value and dynamic initializer are '
                         'absent.')
             except Exception:
                 # HasTraits should call set_default_value to populate
                 # this.  So this should never be reached.
                 raise TraitError('Unexpected error in TraitType: '
                                     'default value not set properly')
             else:
                 return value
 
     def __set__(self, obj, value):
         new_value = self._validate(obj, value)
         old_value = self.__get__(obj)
         if old_value != new_value:
             obj._trait_values[self.name] = new_value
             obj._notify_trait(self.name, old_value, new_value)
 
     def _validate(self, obj, value):
         if hasattr(self, 'validate'):
             return self.validate(obj, value)
         elif hasattr(self, 'is_valid_for'):
             valid = self.is_valid_for(value)
             if valid:
                 return value
             else:
                 raise TraitError('invalid value for type: %r' % value)
         elif hasattr(self, 'value_for'):
             return self.value_for(value)
         else:
             return value
 
     def info(self):
         return self.info_text
 
     def error(self, obj, value):
         if obj is not None:
             e = "The '%s' trait of %s instance must be %s, but a value of %s was specified." \
                 % (self.name, class_of(obj),
                    self.info(), repr_type(value))
         else:
             e = "The '%s' trait must be %s, but a value of %r was specified." \
                 % (self.name, self.info(), repr_type(value))
         raise TraitError(e)
 
     def get_metadata(self, key):
         return getattr(self, '_metadata', {}).get(key, None)
 
     def set_metadata(self, key, value):
         getattr(self, '_metadata', {})[key] = value
 
 
 #-----------------------------------------------------------------------------
 # The HasTraits implementation
 #-----------------------------------------------------------------------------
 
 
 class MetaHasTraits(type):
     """A metaclass for HasTraits.
     
     This metaclass makes sure that any TraitType class attributes are
     instantiated and sets their name attribute.
     """
     
     def __new__(mcls, name, bases, classdict):
         """Create the HasTraits class.
         
         This instantiates all TraitTypes in the class dict and sets their
         :attr:`name` attribute.
         """
         # print "MetaHasTraitlets (mcls, name): ", mcls, name
         # print "MetaHasTraitlets (bases): ", bases
         # print "MetaHasTraitlets (classdict): ", classdict
         for k,v in classdict.iteritems():
             if isinstance(v, TraitType):
                 v.name = k
             elif inspect.isclass(v):
                 if issubclass(v, TraitType):
                     vinst = v()
                     vinst.name = k
                     classdict[k] = vinst
         return super(MetaHasTraits, mcls).__new__(mcls, name, bases, classdict)
 
     def __init__(cls, name, bases, classdict):
         """Finish initializing the HasTraits class.
         
         This sets the :attr:`this_class` attribute of each TraitType in the
         class dict to the newly created class ``cls``.
         """
         for k, v in classdict.iteritems():
             if isinstance(v, TraitType):
                 v.this_class = cls
         super(MetaHasTraits, cls).__init__(name, bases, classdict)
 
 class HasTraits(object):
 
     __metaclass__ = MetaHasTraits
 
     def __new__(cls, **kw):
         # This is needed because in Python 2.6 object.__new__ only accepts
         # the cls argument.
         new_meth = super(HasTraits, cls).__new__
         if new_meth is object.__new__:
             inst = new_meth(cls)
         else:
             inst = new_meth(cls, **kw)
         inst._trait_values = {}
         inst._trait_notifiers = {}
         inst._trait_dyn_inits = {}
         # Here we tell all the TraitType instances to set their default
         # values on the instance. 
         for key in dir(cls):
             # Some descriptors raise AttributeError like zope.interface's
             # __provides__ attributes even though they exist.  This causes
             # AttributeErrors even though they are listed in dir(cls).
             try:
                 value = getattr(cls, key)
             except AttributeError:
                 pass
             else:
                 if isinstance(value, TraitType):
                     value.instance_init(inst)
 
         return inst
 
     def __init__(self, **kw):
         # Allow trait values to be set using keyword arguments.
         # We need to use setattr for this to trigger validation and
         # notifications.
         for key, value in kw.iteritems():
             setattr(self, key, value)
 
     def _notify_trait(self, name, old_value, new_value):
 
         # First dynamic ones
         callables = self._trait_notifiers.get(name,[])
         more_callables = self._trait_notifiers.get('anytrait',[])
         callables.extend(more_callables)
 
         # Now static ones
         try:
             cb = getattr(self, '_%s_changed' % name)
         except:
             pass
         else:
             callables.append(cb)
 
         # Call them all now
         for c in callables:
             # Traits catches and logs errors here.  I allow them to raise
             if callable(c):
                 argspec = inspect.getargspec(c)
                 nargs = len(argspec[0])
                 # Bound methods have an additional 'self' argument
                 # I don't know how to treat unbound methods, but they
                 # can't really be used for callbacks.
                 if isinstance(c, types.MethodType):
                     offset = -1
                 else:
                     offset = 0
                 if nargs + offset == 0:
                     c()
                 elif nargs + offset == 1:
                     c(name)
                 elif nargs + offset == 2:
                     c(name, new_value)
                 elif nargs + offset == 3:
                     c(name, old_value, new_value)
                 else:
                     raise TraitError('a trait changed callback '
                                         'must have 0-3 arguments.')
             else:
                 raise TraitError('a trait changed callback '
                                     'must be callable.')
                 
 
     def _add_notifiers(self, handler, name):
         if not self._trait_notifiers.has_key(name):
             nlist = []
             self._trait_notifiers[name] = nlist
         else:
             nlist = self._trait_notifiers[name]
         if handler not in nlist:
             nlist.append(handler)
 
     def _remove_notifiers(self, handler, name):
         if self._trait_notifiers.has_key(name):
             nlist = self._trait_notifiers[name]
             try:
                 index = nlist.index(handler)
             except ValueError:
                 pass
             else:
                 del nlist[index]
 
     def on_trait_change(self, handler, name=None, remove=False):
         """Setup a handler to be called when a trait changes.
 
         This is used to setup dynamic notifications of trait changes.
         
         Static handlers can be created by creating methods on a HasTraits
         subclass with the naming convention '_[traitname]_changed'.  Thus,
         to create static handler for the trait 'a', create the method
         _a_changed(self, name, old, new) (fewer arguments can be used, see
         below).
         
         Parameters
         ----------
         handler : callable
             A callable that is called when a trait changes.  Its 
             signature can be handler(), handler(name), handler(name, new)
             or handler(name, old, new).
         name : list, str, None
             If None, the handler will apply to all traits.  If a list
             of str, handler will apply to all names in the list.  If a
             str, the handler will apply just to that name.
         remove : bool
             If False (the default), then install the handler.  If True
             then unintall it.
         """
         if remove:
             names = parse_notifier_name(name)
             for n in names:
                 self._remove_notifiers(handler, n)
         else:
             names = parse_notifier_name(name)
             for n in names:
                 self._add_notifiers(handler, n)
 
     @classmethod
     def class_trait_names(cls, **metadata):
         """Get a list of all the names of this classes traits.
 
         This method is just like the :meth:`trait_names` method, but is unbound.
         """
         return cls.class_traits(**metadata).keys()
 
     @classmethod
     def class_traits(cls, **metadata):
         """Get a list of all the traits of this class.
 
         This method is just like the :meth:`traits` method, but is unbound.
 
         The TraitTypes returned don't know anything about the values
         that the various HasTrait's instances are holding.
 
         This follows the same algorithm as traits does and does not allow
         for any simple way of specifying merely that a metadata name
         exists, but has any value.  This is because get_metadata returns
         None if a metadata key doesn't exist.
         """
         traits = dict([memb for memb in getmembers(cls) if \
                      isinstance(memb[1], TraitType)])
 
         if len(metadata) == 0:
             return traits
 
         for meta_name, meta_eval in metadata.items():
             if type(meta_eval) is not FunctionType:
                 metadata[meta_name] = _SimpleTest(meta_eval)
 
         result = {}
         for name, trait in traits.items():
             for meta_name, meta_eval in metadata.items():
                 if not meta_eval(trait.get_metadata(meta_name)):
                     break
             else:
                 result[name] = trait
 
         return result
 
     def trait_names(self, **metadata):
         """Get a list of all the names of this classes traits."""
         return self.traits(**metadata).keys()
 
     def traits(self, **metadata):
         """Get a list of all the traits of this class.
 
         The TraitTypes returned don't know anything about the values
         that the various HasTrait's instances are holding.
 
         This follows the same algorithm as traits does and does not allow
         for any simple way of specifying merely that a metadata name
         exists, but has any value.  This is because get_metadata returns
         None if a metadata key doesn't exist.
         """
         traits = dict([memb for memb in getmembers(self.__class__) if \
                      isinstance(memb[1], TraitType)])
 
         if len(metadata) == 0:
             return traits
 
         for meta_name, meta_eval in metadata.items():
             if type(meta_eval) is not FunctionType:
                 metadata[meta_name] = _SimpleTest(meta_eval)
 
         result = {}
         for name, trait in traits.items():
             for meta_name, meta_eval in metadata.items():
                 if not meta_eval(trait.get_metadata(meta_name)):
                     break
             else:
                 result[name] = trait
 
         return result
 
     def trait_metadata(self, traitname, key):
         """Get metadata values for trait by key."""
         try:
             trait = getattr(self.__class__, traitname)
         except AttributeError:
             raise TraitError("Class %s does not have a trait named %s" %
                                 (self.__class__.__name__, traitname))
         else:
             return trait.get_metadata(key)
 
 #-----------------------------------------------------------------------------
 # Actual TraitTypes implementations/subclasses
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # TraitTypes subclasses for handling classes and instances of classes
 #-----------------------------------------------------------------------------
 
 
 class ClassBasedTraitType(TraitType):
     """A trait with error reporting for Type, Instance and This."""
 
     def error(self, obj, value):
         kind = type(value)
         if (not py3compat.PY3) and kind is InstanceType:
             msg = 'class %s' % value.__class__.__name__
         else:
             msg = '%s (i.e. %s)' % ( str( kind )[1:-1], repr( value ) )
 
         if obj is not None:
             e = "The '%s' trait of %s instance must be %s, but a value of %s was specified." \
                 % (self.name, class_of(obj),
                    self.info(), msg)
         else:
             e = "The '%s' trait must be %s, but a value of %r was specified." \
                 % (self.name, self.info(), msg)
 
         raise TraitError(e)
 
 
 class Type(ClassBasedTraitType):
     """A trait whose value must be a subclass of a specified class."""
 
     def __init__ (self, default_value=None, klass=None, allow_none=True, **metadata ):
         """Construct a Type trait
 
         A Type trait specifies that its values must be subclasses of
         a particular class.
 
         If only ``default_value`` is given, it is used for the ``klass`` as
         well.
 
         Parameters
         ----------
         default_value : class, str or None
             The default value must be a subclass of klass.  If an str,
             the str must be a fully specified class name, like 'foo.bar.Bah'.
             The string is resolved into real class, when the parent 
             :class:`HasTraits` class is instantiated.
         klass : class, str, None
             Values of this trait must be a subclass of klass.  The klass
             may be specified in a string like: 'foo.bar.MyClass'.
             The string is resolved into real class, when the parent 
             :class:`HasTraits` class is instantiated.
         allow_none : boolean
             Indicates whether None is allowed as an assignable value. Even if
             ``False``, the default value may be ``None``.
         """
         if default_value is None:
             if klass is None:
                 klass = object
         elif klass is None:
             klass = default_value
 
         if not (inspect.isclass(klass) or isinstance(klass, basestring)):
             raise TraitError("A Type trait must specify a class.")
 
         self.klass       = klass
         self._allow_none = allow_none
 
         super(Type, self).__init__(default_value, **metadata)
 
     def validate(self, obj, value):
         """Validates that the value is a valid object instance."""
         try:
             if issubclass(value, self.klass):
                 return value
         except:
             if (value is None) and (self._allow_none):
                 return value
 
         self.error(obj, value)
 
     def info(self):
         """ Returns a description of the trait."""
         if isinstance(self.klass, basestring):
             klass = self.klass
         else:
             klass = self.klass.__name__
         result = 'a subclass of ' + klass
         if self._allow_none:
             return result + ' or None'
         return result
 
     def instance_init(self, obj):
         self._resolve_classes()
         super(Type, self).instance_init(obj)
 
     def _resolve_classes(self):
         if isinstance(self.klass, basestring):
             self.klass = import_item(self.klass)
         if isinstance(self.default_value, basestring):
             self.default_value = import_item(self.default_value)
 
     def get_default_value(self):
         return self.default_value
 
 
 class DefaultValueGenerator(object):
     """A class for generating new default value instances."""
 
     def __init__(self, *args, **kw):
         self.args = args
         self.kw = kw
 
     def generate(self, klass):
         return klass(*self.args, **self.kw)
 
 
 class Instance(ClassBasedTraitType):
     """A trait whose value must be an instance of a specified class.
     
     The value can also be an instance of a subclass of the specified class.
     """
 
     def __init__(self, klass=None, args=None, kw=None, 
                  allow_none=True, **metadata ):
         """Construct an Instance trait.
 
         This trait allows values that are instances of a particular
         class or its sublclasses.  Our implementation is quite different
         from that of enthough.traits as we don't allow instances to be used
         for klass and we handle the ``args`` and ``kw`` arguments differently.
 
         Parameters
         ----------
         klass : class, str
             The class that forms the basis for the trait.  Class names
             can also be specified as strings, like 'foo.bar.Bar'.
         args : tuple
             Positional arguments for generating the default value.
         kw : dict
             Keyword arguments for generating the default value.
         allow_none : bool
             Indicates whether None is allowed as a value.
 
         Default Value
         -------------
         If both ``args`` and ``kw`` are None, then the default value is None.
         If ``args`` is a tuple and ``kw`` is a dict, then the default is
         created as ``klass(*args, **kw)``.  If either ``args`` or ``kw`` is 
         not (but not both), None is replace by ``()`` or ``{}``.
         """
 
         self._allow_none = allow_none
 
         if (klass is None) or (not (inspect.isclass(klass) or isinstance(klass, basestring))):
             raise TraitError('The klass argument must be a class'
                                 ' you gave: %r' % klass)
         self.klass = klass
         
         # self.klass is a class, so handle default_value
         if args is None and kw is None:
             default_value = None
         else:
             if args is None:
                 # kw is not None
                 args = ()
             elif kw is None:
                 # args is not None
                 kw = {}
         
             if not isinstance(kw, dict):
                 raise TraitError("The 'kw' argument must be a dict or None.")
             if not isinstance(args, tuple):
                 raise TraitError("The 'args' argument must be a tuple or None.")
             
             default_value = DefaultValueGenerator(*args, **kw)
 
         super(Instance, self).__init__(default_value, **metadata)
 
     def validate(self, obj, value):
         if value is None:
             if self._allow_none:
                 return value
             self.error(obj, value)
 
         if isinstance(value, self.klass):
             return value
         else:
             self.error(obj, value)
 
     def info(self):
         if isinstance(self.klass, basestring):
             klass = self.klass
         else:
             klass = self.klass.__name__
         result = class_of(klass)
         if self._allow_none:
             return result + ' or None'
 
         return result
 
     def instance_init(self, obj):
         self._resolve_classes()
         super(Instance, self).instance_init(obj)
 
     def _resolve_classes(self):
         if isinstance(self.klass, basestring):
             self.klass = import_item(self.klass)
 
     def get_default_value(self):
         """Instantiate a default value instance.
         
         This is called when the containing HasTraits classes'
         :meth:`__new__` method is called to ensure that a unique instance
         is created for each HasTraits instance.
         """
         dv  = self.default_value
         if isinstance(dv, DefaultValueGenerator):
             return dv.generate(self.klass)
         else:
             return dv
 
 
 class This(ClassBasedTraitType):
     """A trait for instances of the class containing this trait.
 
     Because how how and when class bodies are executed, the ``This``
     trait can only have a default value of None.  This, and because we 
     always validate default values, ``allow_none`` is *always* true.
     """
 
     info_text = 'an instance of the same type as the receiver or None'
 
     def __init__(self, **metadata):
         super(This, self).__init__(None, **metadata)
 
     def validate(self, obj, value):
         # What if value is a superclass of obj.__class__?  This is
         # complicated if it was the superclass that defined the This
         # trait.
         if isinstance(value, self.this_class) or (value is None):
             return value
         else:
             self.error(obj, value)
 
 
 #-----------------------------------------------------------------------------
 # Basic TraitTypes implementations/subclasses
 #-----------------------------------------------------------------------------
 
 
 class Any(TraitType):
     default_value = None
     info_text = 'any value'
 
 
 class Int(TraitType):
     """A integer trait."""
 
     default_value = 0
     info_text = 'an integer'
 
     def validate(self, obj, value):
         if isinstance(value, int):
             return value
         self.error(obj, value)
 
 class CInt(Int):
     """A casting version of the int trait."""
 
     def validate(self, obj, value):
         try:
             return int(value)
         except:
             self.error(obj, value)
 
-if not py3compat.PY3:
+if py3compat.PY3:
+    Long, CLong = Int, CInt
+else:
     class Long(TraitType):
         """A long integer trait."""
 
         default_value = 0L
         info_text = 'a long'
 
         def validate(self, obj, value):
             if isinstance(value, long):
                 return value
             if isinstance(value, int):
                 return long(value)
             self.error(obj, value)
 
 
     class CLong(Long):
         """A casting version of the long integer trait."""
 
         def validate(self, obj, value):
             try:
                 return long(value)
             except:
                 self.error(obj, value)
 
 
 class Float(TraitType):
     """A float trait."""
 
     default_value = 0.0
     info_text = 'a float'
 
     def validate(self, obj, value):
         if isinstance(value, float):
             return value
         if isinstance(value, int):
             return float(value)
         self.error(obj, value)
 
 
 class CFloat(Float):
     """A casting version of the float trait."""
 
     def validate(self, obj, value):
         try:
             return float(value)
         except:
             self.error(obj, value)
 
 class Complex(TraitType):
     """A trait for complex numbers."""
 
     default_value = 0.0 + 0.0j
     info_text = 'a complex number'
 
     def validate(self, obj, value):
         if isinstance(value, complex):
             return value
         if isinstance(value, (float, int)):
             return complex(value)
         self.error(obj, value)
 
 
 class CComplex(Complex):
     """A casting version of the complex number trait."""
 
     def validate (self, obj, value):
         try:
             return complex(value)
         except:
             self.error(obj, value)
 
 # We should always be explicit about whether we're using bytes or unicode, both
 # for Python 3 conversion and for reliable unicode behaviour on Python 2. So
 # we don't have a Str type.
 class Bytes(TraitType):
     """A trait for byte strings."""
 
     default_value = ''
     info_text = 'a string'
 
     def validate(self, obj, value):
         if isinstance(value, bytes):
             return value
         self.error(obj, value)
 
 
 class CBytes(Bytes):
     """A casting version of the byte string trait."""
 
     def validate(self, obj, value):
         try:
             return bytes(value)
         except:
             self.error(obj, value)
 
 
 class Unicode(TraitType):
     """A trait for unicode strings."""
 
     default_value = u''
     info_text = 'a unicode string'
 
     def validate(self, obj, value):
         if isinstance(value, unicode):
             return value
         if isinstance(value, bytes):
             return unicode(value)
         self.error(obj, value)
 
 
 class CUnicode(Unicode):
     """A casting version of the unicode trait."""
 
     def validate(self, obj, value):
         try:
             return unicode(value)
         except:
             self.error(obj, value)
   
             
 class ObjectName(TraitType):
     """A string holding a valid object name in this version of Python.
     
     This does not check that the name exists in any scope."""
     info_text = "a valid object identifier in Python"
 
     if py3compat.PY3:
         # Python 3:
         coerce_str = staticmethod(lambda _,s: s)
     
     else:
         # Python 2:
         def coerce_str(self, obj, value):
             "In Python 2, coerce ascii-only unicode to str"
             if isinstance(value, unicode):
                 try:
                     return str(value)
                 except UnicodeEncodeError:
                     self.error(obj, value)
             return value
     
     def validate(self, obj, value):
         value = self.coerce_str(obj, value)
         
         if isinstance(value, str) and py3compat.isidentifier(value):
             return value
         self.error(obj, value)
 
 class DottedObjectName(ObjectName):
     """A string holding a valid dotted object name in Python, such as A.b3._c"""
     def validate(self, obj, value):
         value = self.coerce_str(obj, value)
         
         if isinstance(value, str) and py3compat.isidentifier(value, dotted=True):
             return value
         self.error(obj, value)
 
 
 class Bool(TraitType):
     """A boolean (True, False) trait."""
 
     default_value = False
     info_text = 'a boolean'
 
     def validate(self, obj, value):
         if isinstance(value, bool):
             return value
         self.error(obj, value)
 
 
 class CBool(Bool):
     """A casting version of the boolean trait."""
 
     def validate(self, obj, value):
         try:
             return bool(value)
         except:
             self.error(obj, value)
 
 
 class Enum(TraitType):
     """An enum that whose value must be in a given sequence."""
 
     def __init__(self, values, default_value=None, allow_none=True, **metadata):
         self.values = values
         self._allow_none = allow_none
         super(Enum, self).__init__(default_value, **metadata)
 
     def validate(self, obj, value):
         if value is None:
             if self._allow_none:
                 return value
 
         if value in self.values:
                 return value
         self.error(obj, value)
 
     def info(self):
         """ Returns a description of the trait."""
         result = 'any of ' + repr(self.values)
         if self._allow_none:
             return result + ' or None'
         return result
 
 class CaselessStrEnum(Enum):
     """An enum of strings that are caseless in validate."""
 
     def validate(self, obj, value):
         if value is None:
             if self._allow_none:
                 return value
 
         if not isinstance(value, basestring):
             self.error(obj, value)
 
         for v in self.values:
             if v.lower() == value.lower():
                 return v
         self.error(obj, value)
 
 class Container(Instance):
     """An instance of a container (list, set, etc.)
 
     To be subclassed by overriding klass.
     """
     klass = None
     _valid_defaults = SequenceTypes
     _trait = None
 
     def __init__(self, trait=None, default_value=None, allow_none=True,
                 **metadata):
         """Create a container trait type from a list, set, or tuple.
 
         The default value is created by doing ``List(default_value)``,
         which creates a copy of the ``default_value``.
 
         ``trait`` can be specified, which restricts the type of elements
         in the container to that TraitType.
 
         If only one arg is given and it is not a Trait, it is taken as
         ``default_value``:
 
         ``c = List([1,2,3])``
 
         Parameters
         ----------
 
         trait : TraitType [ optional ]
             the type for restricting the contents of the Container.  If unspecified,
             types are not checked.
 
         default_value : SequenceType [ optional ]
             The default value for the Trait.  Must be list/tuple/set, and
             will be cast to the container type.
 
         allow_none : Bool [ default True ]
             Whether to allow the value to be None
 
         **metadata : any
             further keys for extensions to the Trait (e.g. config)
 
         """
         istrait = lambda t: isinstance(t, type) and issubclass(t, TraitType)
 
         # allow List([values]):
         if default_value is None and not istrait(trait):
             default_value = trait
             trait = None
 
         if default_value is None:
             args = ()
         elif isinstance(default_value, self._valid_defaults):
             args = (default_value,)
         else:
             raise TypeError('default value of %s was %s' %(self.__class__.__name__, default_value))
 
         if istrait(trait):
             self._trait = trait()
             self._trait.name = 'element'
         elif trait is not None:
             raise TypeError("`trait` must be a Trait or None, got %s"%repr_type(trait))
 
         super(Container,self).__init__(klass=self.klass, args=args,
                                   allow_none=allow_none, **metadata)
 
     def element_error(self, obj, element, validator):
         e = "Element of the '%s' trait of %s instance must be %s, but a value of %s was specified." \
             % (self.name, class_of(obj), validator.info(), repr_type(element))
         raise TraitError(e)
 
     def validate(self, obj, value):
         value = super(Container, self).validate(obj, value)
         if value is None:
             return value
 
         value = self.validate_elements(obj, value)
 
         return value
 
     def validate_elements(self, obj, value):
         validated = []
         if self._trait is None or isinstance(self._trait, Any):
             return value
         for v in value:
             try:
                 v = self._trait.validate(obj, v)
             except TraitError:
                 self.element_error(obj, v, self._trait)
             else:
                 validated.append(v)
         return self.klass(validated)
 
 
 class List(Container):
     """An instance of a Python list."""
     klass = list
 
     def __init__(self, trait=None, default_value=None, minlen=0, maxlen=sys.maxint,
                 allow_none=True, **metadata):
         """Create a List trait type from a list, set, or tuple.
 
         The default value is created by doing ``List(default_value)``,
         which creates a copy of the ``default_value``.
 
         ``trait`` can be specified, which restricts the type of elements
         in the container to that TraitType.
 
         If only one arg is given and it is not a Trait, it is taken as
         ``default_value``:
 
         ``c = List([1,2,3])``
 
         Parameters
         ----------
 
         trait : TraitType [ optional ]
             the type for restricting the contents of the Container.  If unspecified,
             types are not checked.
 
         default_value : SequenceType [ optional ]
             The default value for the Trait.  Must be list/tuple/set, and
             will be cast to the container type.
 
         minlen : Int [ default 0 ]
             The minimum length of the input list
 
         maxlen : Int [ default sys.maxint ]
             The maximum length of the input list
 
         allow_none : Bool [ default True ]
             Whether to allow the value to be None
 
         **metadata : any
             further keys for extensions to the Trait (e.g. config)
 
         """
         self._minlen = minlen
         self._maxlen = maxlen
         super(List, self).__init__(trait=trait, default_value=default_value,
                                 allow_none=allow_none, **metadata)
 
     def length_error(self, obj, value):
         e = "The '%s' trait of %s instance must be of length %i <= L <= %i, but a value of %s was specified." \
             % (self.name, class_of(obj), self._minlen, self._maxlen, value)
         raise TraitError(e)
 
     def validate_elements(self, obj, value):
         length = len(value)
         if length < self._minlen or length > self._maxlen:
             self.length_error(obj, value)
 
         return super(List, self).validate_elements(obj, value)
 
 
 class Set(Container):
     """An instance of a Python set."""
     klass = set
 
 class Tuple(Container):
     """An instance of a Python tuple."""
     klass = tuple
 
     def __init__(self, *traits, **metadata):
         """Tuple(*traits, default_value=None, allow_none=True, **medatata)
 
         Create a tuple from a list, set, or tuple.
 
         Create a fixed-type tuple with Traits:
 
         ``t = Tuple(Int, Str, CStr)``
 
         would be length 3, with Int,Str,CStr for each element.
 
         If only one arg is given and it is not a Trait, it is taken as
         default_value:
 
         ``t = Tuple((1,2,3))``
 
         Otherwise, ``default_value`` *must* be specified by keyword.
 
         Parameters
         ----------
 
         *traits : TraitTypes [ optional ]
             the tsype for restricting the contents of the Tuple.  If unspecified,
             types are not checked. If specified, then each positional argument
             corresponds to an element of the tuple.  Tuples defined with traits
             are of fixed length.
 
         default_value : SequenceType [ optional ]
             The default value for the Tuple.  Must be list/tuple/set, and
             will be cast to a tuple. If `traits` are specified, the
             `default_value` must conform to the shape and type they specify.
 
         allow_none : Bool [ default True ]
             Whether to allow the value to be None
 
         **metadata : any
             further keys for extensions to the Trait (e.g. config)
 
         """
         default_value = metadata.pop('default_value', None)
         allow_none = metadata.pop('allow_none', True)
 
         istrait = lambda t: isinstance(t, type) and issubclass(t, TraitType)
 
         # allow Tuple((values,)):
         if len(traits) == 1 and default_value is None and not istrait(traits[0]):
             default_value = traits[0]
             traits = ()
 
         if default_value is None:
             args = ()
         elif isinstance(default_value, self._valid_defaults):
             args = (default_value,)
         else:
             raise TypeError('default value of %s was %s' %(self.__class__.__name__, default_value))
 
         self._traits = []
         for trait in traits:
             t = trait()
             t.name = 'element'
             self._traits.append(t)
 
         if self._traits and default_value is None:
             # don't allow default to be an empty container if length is specified
             args = None
         super(Container,self).__init__(klass=self.klass, args=args,
                                   allow_none=allow_none, **metadata)
 
     def validate_elements(self, obj, value):
         if not self._traits:
             # nothing to validate
             return value
         if len(value) != len(self._traits):
             e = "The '%s' trait of %s instance requires %i elements, but a value of %s was specified." \
                 % (self.name, class_of(obj), len(self._traits), repr_type(value))
             raise TraitError(e)
 
         validated = []
         for t,v in zip(self._traits, value):
             try:
                 v = t.validate(obj, v)
             except TraitError:
                 self.element_error(obj, v, t)
             else:
                 validated.append(v)
         return tuple(validated)
 
 
 class Dict(Instance):
     """An instance of a Python dict."""
 
     def __init__(self, default_value=None, allow_none=True, **metadata):
         """Create a dict trait type from a dict.
 
         The default value is created by doing ``dict(default_value)``, 
         which creates a copy of the ``default_value``.
         """
         if default_value is None:
             args = ((),)
         elif isinstance(default_value, dict):
             args = (default_value,)
         elif isinstance(default_value, SequenceTypes):
             args = (default_value,)
         else:
             raise TypeError('default value of Dict was %s' % default_value)
 
         super(Dict,self).__init__(klass=dict, args=args, 
                                   allow_none=allow_none, **metadata)
 
 class TCPAddress(TraitType):
     """A trait for an (ip, port) tuple.
 
     This allows for both IPv4 IP addresses as well as hostnames.
     """
 
     default_value = ('127.0.0.1', 0)
     info_text = 'an (ip, port) tuple'
 
     def validate(self, obj, value):
         if isinstance(value, tuple):
             if len(value) == 2:
                 if isinstance(value[0], basestring) and isinstance(value[1], int):
                     port = value[1]
                     if port >= 0 and port <= 65535:
                         return value
         self.error(obj, value)