More Python 3 compatibility fixes in core.

IPython/core/formatters.py

@@ -1,619 +1,620 b''
 # -*- coding: utf-8 -*-
 """Display formatters.
 
 
 Authors:
 
 * Robert Kern
 * Brian Granger
 """
 #-----------------------------------------------------------------------------
 # Copyright (c) 2010, IPython Development Team.
 #
 # Distributed under the terms of the Modified BSD License.
 #
 # The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Stdlib imports
 import abc
 import sys
 # We must use StringIO, as cStringIO doesn't handle unicode properly.
 from StringIO import StringIO
 
 # Our own imports
 from IPython.config.configurable import Configurable
 from IPython.lib import pretty
 from IPython.utils.traitlets import Bool, Dict, Int, Unicode, CUnicode, ObjectName
+from IPython.utils.py3compat import unicode_to_str
 
 
 #-----------------------------------------------------------------------------
 # The main DisplayFormatter class
 #-----------------------------------------------------------------------------
 
 
 class DisplayFormatter(Configurable):
 
     # When set to true only the default plain text formatter will be used.
     plain_text_only = Bool(False, config=True)
 
     # A dict of formatter whose keys are format types (MIME types) and whose
     # values are subclasses of BaseFormatter.
     formatters = Dict(config=True)
     def _formatters_default(self):
         """Activate the default formatters."""
         formatter_classes = [
             PlainTextFormatter,
             HTMLFormatter,
             SVGFormatter,
             PNGFormatter,
             JPEGFormatter,
             LatexFormatter,
             JSONFormatter,
             JavascriptFormatter
         ]
         d = {}
         for cls in formatter_classes:
             f = cls(config=self.config)
             d[f.format_type] = f
         return d
 
     def format(self, obj, include=None, exclude=None):
         """Return a format data dict for an object.
 
         By default all format types will be computed.
 
         The following MIME types are currently implemented:
 
         * text/plain
         * text/html
         * text/latex
         * application/json
         * application/javascript
         * image/png
         * image/jpeg
         * image/svg+xml
 
         Parameters
         ----------
         obj : object
             The Python object whose format data will be computed.
         include : list or tuple, optional
             A list of format type strings (MIME types) to include in the
             format data dict. If this is set *only* the format types included
             in this list will be computed.
         exclude : list or tuple, optional
             A list of format type string (MIME types) to exclue in the format
             data dict. If this is set all format types will be computed,
             except for those included in this argument.
 
         Returns
         -------
         format_dict : dict
             A dictionary of key/value pairs, one or each format that was
             generated for the object. The keys are the format types, which
             will usually be MIME type strings and the values and JSON'able
             data structure containing the raw data for the representation in
             that format.
         """
         format_dict = {}
 
         # If plain text only is active
         if self.plain_text_only:
             formatter = self.formatters['text/plain']
             try:
                 data = formatter(obj)
             except:
                 # FIXME: log the exception
                 raise
             if data is not None:
                 format_dict['text/plain'] = data
             return format_dict
 
         for format_type, formatter in self.formatters.items():
             if include is not None:
                 if format_type not in include:
                     continue
             if exclude is not None:
                 if format_type in exclude:
                     continue
             try:
                 data = formatter(obj)
             except:
                 # FIXME: log the exception
                 raise
             if data is not None:
                 format_dict[format_type] = data
         return format_dict
 
     @property
     def format_types(self):
         """Return the format types (MIME types) of the active formatters."""
         return self.formatters.keys()
 
 
 #-----------------------------------------------------------------------------
 # Formatters for specific format types (text, html, svg, etc.)
 #-----------------------------------------------------------------------------
 
 
 class FormatterABC(object):
     """ Abstract base class for Formatters.
 
     A formatter is a callable class that is responsible for computing the
     raw format data for a particular format type (MIME type). For example,
     an HTML formatter would have a format type of `text/html` and would return
     the HTML representation of the object when called.
     """
     __metaclass__ = abc.ABCMeta
 
     # The format type of the data returned, usually a MIME type.
     format_type = 'text/plain'
 
     # Is the formatter enabled...
     enabled = True
 
     @abc.abstractmethod
     def __call__(self, obj):
         """Return a JSON'able representation of the object.
 
         If the object cannot be formatted by this formatter, then return None
         """
         try:
             return repr(obj)
         except TypeError:
             return None
 
 
 class BaseFormatter(Configurable):
     """A base formatter class that is configurable.
 
     This formatter should usually be used as the base class of all formatters.
     It is a traited :class:`Configurable` class and includes an extensible
     API for users to determine how their objects are formatted. The following
     logic is used to find a function to format an given object.
 
     1. The object is introspected to see if it has a method with the name
        :attr:`print_method`. If is does, that object is passed to that method
        for formatting.
     2. If no print method is found, three internal dictionaries are consulted
        to find print method: :attr:`singleton_printers`, :attr:`type_printers`
        and :attr:`deferred_printers`.
 
     Users should use these dictionaries to register functions that will be
     used to compute the format data for their objects (if those objects don't
     have the special print methods). The easiest way of using these
     dictionaries is through the :meth:`for_type` and :meth:`for_type_by_name`
     methods.
 
     If no function/callable is found to compute the format data, ``None`` is
     returned and this format type is not used.
     """
 
     format_type = Unicode('text/plain')
 
     enabled = Bool(True, config=True)
 
     print_method = ObjectName('__repr__')
 
     # The singleton printers.
     # Maps the IDs of the builtin singleton objects to the format functions.
     singleton_printers = Dict(config=True)
     def _singleton_printers_default(self):
         return {}
 
     # The type-specific printers.
     # Map type objects to the format functions.
     type_printers = Dict(config=True)
     def _type_printers_default(self):
         return {}
 
     # The deferred-import type-specific printers.
     # Map (modulename, classname) pairs to the format functions.
     deferred_printers = Dict(config=True)
     def _deferred_printers_default(self):
         return {}
 
     def __call__(self, obj):
         """Compute the format for an object."""
         if self.enabled:
             obj_id = id(obj)
             try:
                 obj_class = getattr(obj, '__class__', None) or type(obj)
                 # First try to find registered singleton printers for the type.
                 try:
                     printer = self.singleton_printers[obj_id]
                 except (TypeError, KeyError):
                     pass
                 else:
                     return printer(obj)
                 # Next look for type_printers.
                 for cls in pretty._get_mro(obj_class):
                     if cls in self.type_printers:
                         return self.type_printers[cls](obj)
                     else:
                         printer = self._in_deferred_types(cls)
                         if printer is not None:
                             return printer(obj)
                 # Finally look for special method names.
                 if hasattr(obj_class, self.print_method):
                     printer = getattr(obj_class, self.print_method)
                     return printer(obj)
                 return None
             except Exception:
                 pass
         else:
             return None
 
     def for_type(self, typ, func):
         """Add a format function for a given type.
 
         Parameters
         -----------
         typ : class
             The class of the object that will be formatted using `func`.
         func : callable
             The callable that will be called to compute the format data. The
             call signature of this function is simple, it must take the
             object to be formatted and return the raw data for the given
             format. Subclasses may use a different call signature for the
             `func` argument.
         """
         oldfunc = self.type_printers.get(typ, None)
         if func is not None:
             # To support easy restoration of old printers, we need to ignore
             # Nones.
             self.type_printers[typ] = func
         return oldfunc
 
     def for_type_by_name(self, type_module, type_name, func):
         """Add a format function for a type specified by the full dotted
         module and name of the type, rather than the type of the object.
 
         Parameters
         ----------
         type_module : str
             The full dotted name of the module the type is defined in, like
             ``numpy``.
         type_name : str
             The name of the type (the class name), like ``dtype``
         func : callable
             The callable that will be called to compute the format data. The
             call signature of this function is simple, it must take the
             object to be formatted and return the raw data for the given
             format. Subclasses may use a different call signature for the
             `func` argument.
         """
         key = (type_module, type_name)
         oldfunc = self.deferred_printers.get(key, None)
         if func is not None:
             # To support easy restoration of old printers, we need to ignore
             # Nones.
             self.deferred_printers[key] = func
         return oldfunc
 
     def _in_deferred_types(self, cls):
         """
         Check if the given class is specified in the deferred type registry.
 
         Returns the printer from the registry if it exists, and None if the
         class is not in the registry. Successful matches will be moved to the
         regular type registry for future use.
         """
         mod = getattr(cls, '__module__', None)
         name = getattr(cls, '__name__', None)
         key = (mod, name)
         printer = None
         if key in self.deferred_printers:
             # Move the printer over to the regular registry.
             printer = self.deferred_printers.pop(key)
             self.type_printers[cls] = printer
         return printer
 
 
 class PlainTextFormatter(BaseFormatter):
     """The default pretty-printer.
 
     This uses :mod:`IPython.external.pretty` to compute the format data of
     the object. If the object cannot be pretty printed, :func:`repr` is used.
     See the documentation of :mod:`IPython.external.pretty` for details on
     how to write pretty printers.  Here is a simple example::
 
         def dtype_pprinter(obj, p, cycle):
             if cycle:
                 return p.text('dtype(...)')
             if hasattr(obj, 'fields'):
                 if obj.fields is None:
                     p.text(repr(obj))
                 else:
                     p.begin_group(7, 'dtype([')
                     for i, field in enumerate(obj.descr):
                         if i > 0:
                             p.text(',')
                             p.breakable()
                         p.pretty(field)
                     p.end_group(7, '])')
     """
 
     # The format type of data returned.
     format_type = Unicode('text/plain')
 
     # This subclass ignores this attribute as it always need to return
     # something.
     enabled = Bool(True, config=False)
 
     # Look for a _repr_pretty_ methods to use for pretty printing.
     print_method = ObjectName('_repr_pretty_')
 
     # Whether to pretty-print or not.
     pprint = Bool(True, config=True)
 
     # Whether to be verbose or not.
     verbose = Bool(False, config=True)
 
     # The maximum width.
     max_width = Int(79, config=True)
 
     # The newline character.
     newline = Unicode('\n', config=True)
     
     # format-string for pprinting floats
     float_format = Unicode('%r')
     # setter for float precision, either int or direct format-string
     float_precision = CUnicode('', config=True)
     
     def _float_precision_changed(self, name, old, new):
         """float_precision changed, set float_format accordingly.
         
         float_precision can be set by int or str.
         This will set float_format, after interpreting input.
         If numpy has been imported, numpy print precision will also be set.
         
         integer `n` sets format to '%.nf', otherwise, format set directly.
         
         An empty string returns to defaults (repr for float, 8 for numpy).
         
         This parameter can be set via the '%precision' magic.
         """
         
         if '%' in new:
             # got explicit format string
             fmt = new
             try:
                 fmt%3.14159
             except Exception:
                 raise ValueError("Precision must be int or format string, not %r"%new)
         elif new:
             # otherwise, should be an int
             try:
                 i = int(new)
                 assert i >= 0
             except ValueError:
                 raise ValueError("Precision must be int or format string, not %r"%new)
             except AssertionError:
                 raise ValueError("int precision must be non-negative, not %r"%i)
             
             fmt = '%%.%if'%i
             if 'numpy' in sys.modules:
                 # set numpy precision if it has been imported
                 import numpy
                 numpy.set_printoptions(precision=i)
         else:
             # default back to repr
             fmt = '%r'
             if 'numpy' in sys.modules:
                 import numpy
                 # numpy default is 8
                 numpy.set_printoptions(precision=8)
         self.float_format = fmt
 
     # Use the default pretty printers from IPython.external.pretty.
     def _singleton_printers_default(self):
         return pretty._singleton_pprinters.copy()
 
     def _type_printers_default(self):
         d = pretty._type_pprinters.copy()
         d[float] = lambda obj,p,cycle: p.text(self.float_format%obj)
         return d
 
     def _deferred_printers_default(self):
         return pretty._deferred_type_pprinters.copy()
 
     #### FormatterABC interface ####
 
     def __call__(self, obj):
         """Compute the pretty representation of the object."""
         if not self.pprint:
             try:
                 return repr(obj)
             except TypeError:
                 return ''
         else:
             # This uses use StringIO, as cStringIO doesn't handle unicode.
             stream = StringIO()
             # self.newline.encode() is a quick fix for issue gh-597. We need to
             # ensure that stream does not get a mix of unicode and bytestrings,
             # or it will cause trouble.
             printer = pretty.RepresentationPrinter(stream, self.verbose,
-                self.max_width, self.newline.encode(),
+                self.max_width, unicode_to_str(self.newline),
                 singleton_pprinters=self.singleton_printers,
                 type_pprinters=self.type_printers,
                 deferred_pprinters=self.deferred_printers)
             printer.pretty(obj)
             printer.flush()
             return stream.getvalue()
 
 
 class HTMLFormatter(BaseFormatter):
     """An HTML formatter.
 
     To define the callables that compute the HTML representation of your
     objects, define a :meth:`_repr_html_` method or use the :meth:`for_type`
     or :meth:`for_type_by_name` methods to register functions that handle
     this.
 
     The return value of this formatter should be a valid HTML snippet that
     could be injected into an existing DOM. It should *not* include the 
     ```<html>`` or ```<body>`` tags.
     """
     format_type = Unicode('text/html')
 
     print_method = ObjectName('_repr_html_')
 
 
 class SVGFormatter(BaseFormatter):
     """An SVG formatter.
 
     To define the callables that compute the SVG representation of your
     objects, define a :meth:`_repr_svg_` method or use the :meth:`for_type`
     or :meth:`for_type_by_name` methods to register functions that handle
     this.
 
     The return value of this formatter should be valid SVG enclosed in
     ```<svg>``` tags, that could be injected into an existing DOM. It should
     *not* include the ```<html>`` or ```<body>`` tags.
     """
     format_type = Unicode('image/svg+xml')
 
     print_method = ObjectName('_repr_svg_')
 
 
 class PNGFormatter(BaseFormatter):
     """A PNG formatter.
 
     To define the callables that compute the PNG representation of your
     objects, define a :meth:`_repr_png_` method or use the :meth:`for_type`
     or :meth:`for_type_by_name` methods to register functions that handle
     this.
 
     The return value of this formatter should be raw PNG data, *not*
     base64 encoded.
     """
     format_type = Unicode('image/png')
 
     print_method = ObjectName('_repr_png_')
 
 
 class JPEGFormatter(BaseFormatter):
     """A JPEG formatter.
 
     To define the callables that compute the JPEG representation of your
     objects, define a :meth:`_repr_jpeg_` method or use the :meth:`for_type`
     or :meth:`for_type_by_name` methods to register functions that handle
     this.
 
     The return value of this formatter should be raw JPEG data, *not*
     base64 encoded.
     """
     format_type = Unicode('image/jpeg')
 
     print_method = ObjectName('_repr_jpeg_')
 
 
 class LatexFormatter(BaseFormatter):
     """A LaTeX formatter.
 
     To define the callables that compute the LaTeX representation of your
     objects, define a :meth:`_repr_latex_` method or use the :meth:`for_type`
     or :meth:`for_type_by_name` methods to register functions that handle
     this.
 
     The return value of this formatter should be a valid LaTeX equation,
     enclosed in either ```$``` or ```$$```.
     """
     format_type = Unicode('text/latex')
 
     print_method = ObjectName('_repr_latex_')
 
 
 class JSONFormatter(BaseFormatter):
     """A JSON string formatter.
 
     To define the callables that compute the JSON string representation of
     your objects, define a :meth:`_repr_json_` method or use the :meth:`for_type`
     or :meth:`for_type_by_name` methods to register functions that handle
     this.
 
     The return value of this formatter should be a valid JSON string.
     """
     format_type = Unicode('application/json')
 
     print_method = ObjectName('_repr_json_')
 
 
 class JavascriptFormatter(BaseFormatter):
     """A Javascript formatter.
 
     To define the callables that compute the Javascript representation of
     your objects, define a :meth:`_repr_javascript_` method or use the 
     :meth:`for_type` or :meth:`for_type_by_name` methods to register functions
     that handle this.
 
     The return value of this formatter should be valid Javascript code and
     should *not* be enclosed in ```<script>``` tags.
     """
     format_type = Unicode('application/javascript')
 
     print_method = ObjectName('_repr_javascript_')
 
 FormatterABC.register(BaseFormatter)
 FormatterABC.register(PlainTextFormatter)
 FormatterABC.register(HTMLFormatter)
 FormatterABC.register(SVGFormatter)
 FormatterABC.register(PNGFormatter)
 FormatterABC.register(JPEGFormatter)
 FormatterABC.register(LatexFormatter)
 FormatterABC.register(JSONFormatter)
 FormatterABC.register(JavascriptFormatter)
 
 
 def format_display_data(obj, include=None, exclude=None):
     """Return a format data dict for an object.
 
     By default all format types will be computed.
 
     The following MIME types are currently implemented:
 
     * text/plain
     * text/html
     * text/latex
     * application/json
     * application/javascript
     * image/png
     * image/jpeg
     * image/svg+xml
 
     Parameters
     ----------
     obj : object
         The Python object whose format data will be computed.
 
     Returns
     -------
     format_dict : dict
         A dictionary of key/value pairs, one or each format that was
         generated for the object. The keys are the format types, which
         will usually be MIME type strings and the values and JSON'able
         data structure containing the raw data for the representation in
         that format.
     include : list or tuple, optional
         A list of format type strings (MIME types) to include in the
         format data dict. If this is set *only* the format types included
         in this list will be computed.
     exclude : list or tuple, optional
         A list of format type string (MIME types) to exclue in the format
         data dict. If this is set all format types will be computed,
         except for those included in this argument.
     """
     from IPython.core.interactiveshell import InteractiveShell
 
     InteractiveShell.instance().display_formatter.format(
         obj,
         include,
         exclude
     )
 

IPython/core/inputsplitter.py

@@ -1,892 +1,892 b''
 """Analysis of text input into executable blocks.
 
 The main class in this module, :class:`InputSplitter`, is designed to break
 input from either interactive, line-by-line environments or block-based ones,
 into standalone blocks that can be executed by Python as 'single' statements
 (thus triggering sys.displayhook).
 
 A companion, :class:`IPythonInputSplitter`, provides the same functionality but
 with full support for the extended IPython syntax (magics, system calls, etc).
 
 For more details, see the class docstring below.
 
 Syntax Transformations
 ----------------------
 
 One of the main jobs of the code in this file is to apply all syntax
 transformations that make up 'the IPython language', i.e. magics, shell
 escapes, etc.  All transformations should be implemented as *fully stateless*
 entities, that simply take one line as their input and return a line.
 Internally for implementation purposes they may be a normal function or a
 callable object, but the only input they receive will be a single line and they
 should only return a line, without holding any data-dependent state between
 calls.
 
 As an example, the EscapedTransformer is a class so we can more clearly group
 together the functionality of dispatching to individual functions based on the
 starting escape character, but the only method for public use is its call
 method.
 
 
 ToDo
 ----
 
 - Should we make push() actually raise an exception once push_accepts_more()
   returns False?
 
 - Naming cleanups.  The tr_* names aren't the most elegant, though now they are
   at least just attributes of a class so not really very exposed.
 
 - Think about the best way to support dynamic things: automagic, autocall,
   macros, etc.
 
 - Think of a better heuristic for the application of the transforms in
   IPythonInputSplitter.push() than looking at the buffer ending in ':'.  Idea:
   track indentation change events (indent, dedent, nothing) and apply them only
   if the indentation went up, but not otherwise.
 
 - Think of the cleanest way for supporting user-specified transformations (the
   user prefilters we had before).
 
 Authors
 -------
 
 * Fernando Perez
 * Brian Granger
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010  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.
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 # stdlib
 import ast
 import codeop
 import re
 import sys
 import tokenize
 from StringIO import StringIO
 
 # IPython modules
 from IPython.utils.text import make_quoted_expr
+from IPython.utils.py3compat import cast_unicode
 
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 
 # The escape sequences that define the syntax transformations IPython will
 # apply to user input.  These can NOT be just changed here: many regular
 # expressions and other parts of the code may use their hardcoded values, and
 # for all intents and purposes they constitute the 'IPython syntax', so they
 # should be considered fixed.
 
 ESC_SHELL  = '!'     # Send line to underlying system shell
 ESC_SH_CAP = '!!'    # Send line to system shell and capture output
 ESC_HELP   = '?'     # Find information about object
 ESC_HELP2  = '??'    # Find extra-detailed information about object
 ESC_MAGIC  = '%'     # Call magic function
 ESC_QUOTE  = ','     # Split args on whitespace, quote each as string and call
 ESC_QUOTE2 = ';'     # Quote all args as a single string, call
 ESC_PAREN  = '/'     # Call first argument with rest of line as arguments
 
 #-----------------------------------------------------------------------------
 # Utilities
 #-----------------------------------------------------------------------------
 
 # FIXME: These are general-purpose utilities that later can be moved to the
 # general ward.  Kept here for now because we're being very strict about test
 # coverage with this code, and this lets us ensure that we keep 100% coverage
 # while developing.
 
 # compiled regexps for autoindent management
 dedent_re = re.compile('|'.join([
     r'^\s+raise(\s.*)?$', # raise statement (+ space + other stuff, maybe)
     r'^\s+raise\([^\)]*\).*$', # wacky raise with immediate open paren
     r'^\s+return(\s.*)?$', # normal return (+ space + other stuff, maybe)
     r'^\s+return\([^\)]*\).*$', # wacky return with immediate open paren
     r'^\s+pass\s*$' # pass (optionally followed by trailing spaces)
 ]))
 ini_spaces_re = re.compile(r'^([ \t\r\f\v]+)')
 
 # regexp to match pure comment lines so we don't accidentally insert 'if 1:'
 # before pure comments
 comment_line_re = re.compile('^\s*\#')
 
 
 def num_ini_spaces(s):
     """Return the number of initial spaces in a string.
 
     Note that tabs are counted as a single space.  For now, we do *not* support
     mixing of tabs and spaces in the user's input.
 
     Parameters
     ----------
     s : string
 
     Returns
     -------
     n : int
     """
 
     ini_spaces = ini_spaces_re.match(s)
     if ini_spaces:
         return ini_spaces.end()
     else:
         return 0
 
 
 def remove_comments(src):
     """Remove all comments from input source.
 
     Note: comments are NOT recognized inside of strings!
 
     Parameters
     ----------
     src : string
       A single or multiline input string.
 
     Returns
     -------
     String with all Python comments removed.
     """
 
     return re.sub('#.*', '', src)
     
 def has_comment(src):
     """Indicate whether an input line has (i.e. ends in, or is) a comment.
     
     This uses tokenize, so it can distinguish comments from # inside strings.
     
     Parameters
     ----------
     src : string
       A single line input string.
     
     Returns
     -------
     Boolean: True if source has a comment.
     """
     readline = StringIO(src).readline
     toktypes = set()
     try:
         for t in tokenize.generate_tokens(readline):
             toktypes.add(t[0])
     except tokenize.TokenError:
         pass
     return(tokenize.COMMENT in toktypes)
 
 
 def get_input_encoding():
     """Return the default standard input encoding.
 
     If sys.stdin has no encoding, 'ascii' is returned."""
     # There are strange environments for which sys.stdin.encoding is None. We
     # ensure that a valid encoding is returned.
     encoding = getattr(sys.stdin, 'encoding', None)
     if encoding is None:
         encoding = 'ascii'
     return encoding
 
 #-----------------------------------------------------------------------------
 # Classes and functions for normal Python syntax handling
 #-----------------------------------------------------------------------------
 
 class InputSplitter(object):
     """An object that can accumulate lines of Python source before execution.
 
     This object is designed to be fed python source line-by-line, using
        :meth:`push`. It will return on each push whether the currently pushed
        code could be executed already. In addition, it provides a method called
        :meth:`push_accepts_more` that can be used to query whether more input
        can be pushed into a single interactive block.
 
     This is a simple example of how an interactive terminal-based client can use
     this tool::
 
         isp = InputSplitter()
         while isp.push_accepts_more():
             indent = ' '*isp.indent_spaces
             prompt = '>>> ' + indent
             line = indent + raw_input(prompt)
             isp.push(line)
         print 'Input source was:\n', isp.source_reset(),
     """
     # Number of spaces of indentation computed from input that has been pushed
     # so far.  This is the attributes callers should query to get the current
     # indentation level, in order to provide auto-indent facilities.
     indent_spaces = 0
     # String, indicating the default input encoding.  It is computed by default
     # at initialization time via get_input_encoding(), but it can be reset by a
     # client with specific knowledge of the encoding.
     encoding = ''
     # String where the current full source input is stored, properly encoded.
     # Reading this attribute is the normal way of querying the currently pushed
     # source code, that has been properly encoded.
     source = ''
     # Code object corresponding to the current source.  It is automatically
     # synced to the source, so it can be queried at any time to obtain the code
     # object; it will be None if the source doesn't compile to valid Python.
     code = None
     # Input mode
     input_mode = 'line'
     
     # Private attributes
     
     # List with lines of input accumulated so far
     _buffer = None
     # Command compiler
     _compile = None
     # Mark when input has changed indentation all the way back to flush-left
     _full_dedent = False
     # Boolean indicating whether the current block is complete
     _is_complete = None
     
     def __init__(self, input_mode=None):
         """Create a new InputSplitter instance.
 
         Parameters
         ----------
         input_mode : str
 
           One of ['line', 'cell']; default is 'line'.
 
        The input_mode parameter controls how new inputs are used when fed via
        the :meth:`push` method:
 
        - 'line': meant for line-oriented clients, inputs are appended one at a
          time to the internal buffer and the whole buffer is compiled.
 
        - 'cell': meant for clients that can edit multi-line 'cells' of text at
           a time.  A cell can contain one or more blocks that can be compile in
           'single' mode by Python.  In this mode, each new input new input
           completely replaces all prior inputs.  Cell mode is thus equivalent
           to prepending a full reset() to every push() call.
         """
         self._buffer = []
         self._compile = codeop.CommandCompiler()
         self.encoding = get_input_encoding()
         self.input_mode = InputSplitter.input_mode if input_mode is None \
                           else input_mode
 
     def reset(self):
         """Reset the input buffer and associated state."""
         self.indent_spaces = 0
         self._buffer[:] = []
         self.source = ''
         self.code = None
         self._is_complete = False
         self._full_dedent = False
 
     def source_reset(self):
         """Return the input source and perform a full reset.
         """
         out = self.source
         self.reset()
         return out
 
     def push(self, lines):
         """Push one or more lines of input.
 
         This stores the given lines and returns a status code indicating
         whether the code forms a complete Python block or not.
 
         Any exceptions generated in compilation are swallowed, but if an
         exception was produced, the method returns True.
 
         Parameters
         ----------
         lines : string
           One or more lines of Python input.
         
         Returns
         -------
         is_complete : boolean
           True if the current input source (the result of the current input
         plus prior inputs) forms a complete Python execution block.  Note that
         this value is also stored as a private attribute (_is_complete), so it
         can be queried at any time.
         """
         if self.input_mode == 'cell':
             self.reset()
         
         self._store(lines)
         source = self.source
 
         # Before calling _compile(), reset the code object to None so that if an
         # exception is raised in compilation, we don't mislead by having
         # inconsistent code/source attributes.
         self.code, self._is_complete = None, None
 
         # Honor termination lines properly
         if source.rstrip().endswith('\\'):
             return False
 
         self._update_indent(lines)
         try:
             self.code = self._compile(source, symbol="exec")
         # Invalid syntax can produce any of a number of different errors from
         # inside the compiler, so we have to catch them all.  Syntax errors
         # immediately produce a 'ready' block, so the invalid Python can be
         # sent to the kernel for evaluation with possible ipython
         # special-syntax conversion.
         except (SyntaxError, OverflowError, ValueError, TypeError,
                 MemoryError):
             self._is_complete = True
         else:
             # Compilation didn't produce any exceptions (though it may not have
             # given a complete code object)
             self._is_complete = self.code is not None
 
         return self._is_complete
 
     def push_accepts_more(self):
         """Return whether a block of interactive input can accept more input.
 
         This method is meant to be used by line-oriented frontends, who need to
         guess whether a block is complete or not based solely on prior and
         current input lines.  The InputSplitter considers it has a complete
         interactive block and will not accept more input only when either a
         SyntaxError is raised, or *all* of the following are true:
 
         1. The input compiles to a complete statement.
         
         2. The indentation level is flush-left (because if we are indented,
            like inside a function definition or for loop, we need to keep
            reading new input).
           
         3. There is one extra line consisting only of whitespace.
 
         Because of condition #3, this method should be used only by
         *line-oriented* frontends, since it means that intermediate blank lines
         are not allowed in function definitions (or any other indented block).
 
         If the current input produces a syntax error, this method immediately
         returns False but does *not* raise the syntax error exception, as
         typically clients will want to send invalid syntax to an execution
         backend which might convert the invalid syntax into valid Python via
         one of the dynamic IPython mechanisms.
         """
 
         # With incomplete input, unconditionally accept more
         if not self._is_complete:
             return True
 
         # If we already have complete input and we're flush left, the answer
         # depends.  In line mode, if there hasn't been any indentation,
         # that's it. If we've come back from some indentation, we need
         # the blank final line to finish.
         # In cell mode, we need to check how many blocks the input so far
         # compiles into, because if there's already more than one full
         # independent block of input, then the client has entered full
         # 'cell' mode and is feeding lines that each is complete.  In this
         # case we should then keep accepting. The Qt terminal-like console
         # does precisely this, to provide the convenience of terminal-like
         # input of single expressions, but allowing the user (with a
         # separate keystroke) to switch to 'cell' mode and type multiple
         # expressions in one shot.
         if self.indent_spaces==0:
             if self.input_mode=='line':
                 if not self._full_dedent:
                     return False
             else:
                 try:
                     code_ast = ast.parse(u''.join(self._buffer))
                 except Exception:
                     return False
                 else:
                     if len(code_ast.body) == 1:
                         return False
 
         # When input is complete, then termination is marked by an extra blank
         # line at the end.
         last_line = self.source.splitlines()[-1]
         return bool(last_line and not last_line.isspace())
 
     #------------------------------------------------------------------------
     # Private interface
     #------------------------------------------------------------------------
 
     def _find_indent(self, line):
         """Compute the new indentation level for a single line.
 
         Parameters
         ----------
         line : str
           A single new line of non-whitespace, non-comment Python input.
           
         Returns
         -------
         indent_spaces : int
           New value for the indent level (it may be equal to self.indent_spaces
         if indentation doesn't change.
 
         full_dedent : boolean
           Whether the new line causes a full flush-left dedent.
         """
         indent_spaces = self.indent_spaces
         full_dedent = self._full_dedent
         
         inisp = num_ini_spaces(line)
         if inisp < indent_spaces:
             indent_spaces = inisp
             if indent_spaces <= 0:
                 #print 'Full dedent in text',self.source # dbg
                 full_dedent = True
 
         if line.rstrip()[-1] == ':':
             indent_spaces += 4
         elif dedent_re.match(line):
             indent_spaces -= 4
             if indent_spaces <= 0:
                 full_dedent = True
 
         # Safety
         if indent_spaces < 0:
             indent_spaces = 0
             #print 'safety' # dbg
             
         return indent_spaces, full_dedent
     
     def _update_indent(self, lines):
         for line in remove_comments(lines).splitlines():
             if line and not line.isspace():
                 self.indent_spaces, self._full_dedent = self._find_indent(line)
 
     def _store(self, lines, buffer=None, store='source'):
         """Store one or more lines of input.
 
         If input lines are not newline-terminated, a newline is automatically
         appended."""
         
         if buffer is None:
             buffer = self._buffer
             
         if lines.endswith('\n'):
             buffer.append(lines)
         else:
             buffer.append(lines+'\n')
         setattr(self, store, self._set_source(buffer))
 
     def _set_source(self, buffer):
         return u''.join(buffer)
 
 
 #-----------------------------------------------------------------------------
 # Functions and classes for IPython-specific syntactic support
 #-----------------------------------------------------------------------------
 
 # RegExp for splitting line contents into pre-char//first word-method//rest.
 # For clarity, each group in on one line.
 
 line_split = re.compile("""
              ^(\s*)              # any leading space
              ([,;/%]|!!?|\?\??)  # escape character or characters
              \s*(%?[\w\.\*]*)    # function/method, possibly with leading %
                                  # to correctly treat things like '?%magic'
              (\s+.*$|$)          # rest of line
              """, re.VERBOSE)
 
 
 def split_user_input(line):
     """Split user input into early whitespace, esc-char, function part and rest.
 
     This is currently handles lines with '=' in them in a very inconsistent
     manner.
 
     Examples
     ========
     >>> split_user_input('x=1')
     ('', '', 'x=1', '')
     >>> split_user_input('?')
     ('', '?', '', '')
     >>> split_user_input('??')
     ('', '??', '', '')
     >>> split_user_input(' ?')
     (' ', '?', '', '')
     >>> split_user_input(' ??')
     (' ', '??', '', '')
     >>> split_user_input('??x')
     ('', '??', 'x', '')
     >>> split_user_input('?x=1')
     ('', '', '?x=1', '')
     >>> split_user_input('!ls')
     ('', '!', 'ls', '')
     >>> split_user_input('  !ls')
     ('  ', '!', 'ls', '')
     >>> split_user_input('!!ls')
     ('', '!!', 'ls', '')
     >>> split_user_input('  !!ls')
     ('  ', '!!', 'ls', '')
     >>> split_user_input(',ls')
     ('', ',', 'ls', '')
     >>> split_user_input(';ls')
     ('', ';', 'ls', '')
     >>> split_user_input('  ;ls')
     ('  ', ';', 'ls', '')
     >>> split_user_input('f.g(x)')
     ('', '', 'f.g(x)', '')
     >>> split_user_input('f.g (x)')
     ('', '', 'f.g', '(x)')
     >>> split_user_input('?%hist')
     ('', '?', '%hist', '')
     >>> split_user_input('?x*')
     ('', '?', 'x*', '')
     """
     match = line_split.match(line)
     if match:
         lspace, esc, fpart, rest = match.groups()
     else:
         # print "match failed for line '%s'" % line
         try:
             fpart, rest = line.split(None, 1)
         except ValueError:
             # print "split failed for line '%s'" % line
             fpart, rest = line,''
         lspace = re.match('^(\s*)(.*)', line).groups()[0]
         esc = ''
 
     # fpart has to be a valid python identifier, so it better be only pure
     # ascii, no unicode:
     try:
         fpart = fpart.encode('ascii')
     except UnicodeEncodeError:
         lspace = unicode(lspace)
         rest = fpart + u' ' + rest
         fpart = u''
 
     #print 'line:<%s>' % line # dbg
     #print 'esc <%s> fpart <%s> rest <%s>' % (esc,fpart.strip(),rest) # dbg
     return lspace, esc, fpart.strip(), rest.lstrip()
 
 
 # The escaped translators ALL receive a line where their own escape has been
 # stripped.  Only '?' is valid at the end of the line, all others can only be
 # placed at the start.
 
 class LineInfo(object):
     """A single line of input and associated info.
 
     This is a utility class that mostly wraps the output of
     :func:`split_user_input` into a convenient object to be passed around
     during input transformations.
 
     Includes the following as properties: 
 
     line
       The original, raw line
 
     lspace
       Any early whitespace before actual text starts.
 
     esc
       The initial esc character (or characters, for double-char escapes like
       '??' or '!!').
     
     fpart
       The 'function part', which is basically the maximal initial sequence
       of valid python identifiers and the '.' character.  This is what is
       checked for alias and magic transformations, used for auto-calling,
       etc.
     
     rest
       Everything else on the line.
     """
     def __init__(self, line):
         self.line = line
         self.lspace, self.esc, self.fpart, self.rest = \
                              split_user_input(line)
 
     def __str__(self):                                                         
         return "LineInfo [%s|%s|%s|%s]" % (self.lspace, self.esc,
                                            self.fpart, self.rest)
 
 
 # Transformations of the special syntaxes that don't rely on an explicit escape
 # character but instead on patterns on the input line
 
 # The core transformations are implemented as standalone functions that can be
 # tested and validated in isolation.  Each of these uses a regexp, we
 # pre-compile these and keep them close to each function definition for clarity
 
 _assign_system_re = re.compile(r'(?P<lhs>(\s*)([\w\.]+)((\s*,\s*[\w\.]+)*))'
                                r'\s*=\s*!\s*(?P<cmd>.*)')
 
 def transform_assign_system(line):
     """Handle the `files = !ls` syntax."""
     m = _assign_system_re.match(line)
     if m is not None:
         cmd = m.group('cmd')
         lhs = m.group('lhs')
         expr = make_quoted_expr(cmd)
         new_line = '%s = get_ipython().getoutput(%s)' % (lhs, expr)
         return new_line
     return line
 
 
 _assign_magic_re = re.compile(r'(?P<lhs>(\s*)([\w\.]+)((\s*,\s*[\w\.]+)*))'
                                r'\s*=\s*%\s*(?P<cmd>.*)')
 
 def transform_assign_magic(line):
     """Handle the `a = %who` syntax."""
     m = _assign_magic_re.match(line)
     if m is not None:
         cmd = m.group('cmd')
         lhs = m.group('lhs')
         expr = make_quoted_expr(cmd)
         new_line = '%s = get_ipython().magic(%s)' % (lhs, expr)
         return new_line
     return line
 
 
 _classic_prompt_re = re.compile(r'^([ \t]*>>> |^[ \t]*\.\.\. )')
 
 def transform_classic_prompt(line):
     """Handle inputs that start with '>>> ' syntax."""
 
     if not line or line.isspace():
         return line
     m = _classic_prompt_re.match(line)
     if m:
         return line[len(m.group(0)):]
     else:
         return line
 
 
 _ipy_prompt_re = re.compile(r'^([ \t]*In \[\d+\]: |^[ \t]*\ \ \ \.\.\.+: )')
 
 def transform_ipy_prompt(line):
     """Handle inputs that start classic IPython prompt syntax."""
 
     if not line or line.isspace():
         return line
     #print 'LINE:  %r' % line # dbg
     m = _ipy_prompt_re.match(line)
     if m:
         #print 'MATCH! %r -> %r' % (line, line[len(m.group(0)):]) # dbg
         return line[len(m.group(0)):]
     else:
         return line
 
 
 def _make_help_call(target, esc, lspace, next_input=None):
     """Prepares a pinfo(2)/psearch call from a target name and the escape
     (i.e. ? or ??)"""
     method  = 'pinfo2' if esc == '??' \
                 else 'psearch' if '*' in target \
                 else 'pinfo'
         
     if next_input:
         tpl = '%sget_ipython().magic(u"%s %s", next_input=%s)'
         return tpl % (lspace, method, target, make_quoted_expr(next_input))
     else:
         return '%sget_ipython().magic(u"%s %s")' % (lspace, method, target)
 
 _initial_space_re = re.compile(r'\s*')
 _help_end_re = re.compile(r"""(%?
                               [a-zA-Z_*][a-zA-Z0-9_*]*       # Variable name
                               (\.[a-zA-Z_*][a-zA-Z0-9_*]*)*   # .etc.etc
                               )
                               (\?\??)$                       # ? or ??""",
                               re.VERBOSE)
 def transform_help_end(line):
     """Translate lines with ?/?? at the end"""
     m = _help_end_re.search(line)
     if m is None or has_comment(line):
         return line
     target = m.group(1)
     esc = m.group(3)
     lspace = _initial_space_re.match(line).group(0)
     newline = _make_help_call(target, esc, lspace)
     
     # If we're mid-command, put it back on the next prompt for the user.
     next_input = line.rstrip('?') if line.strip() != m.group(0) else None
         
     return _make_help_call(target, esc, lspace, next_input)
 
 
 class EscapedTransformer(object):
     """Class to transform lines that are explicitly escaped out."""
 
     def __init__(self):
         tr = { ESC_SHELL  : self._tr_system,
                ESC_SH_CAP : self._tr_system2,
                ESC_HELP   : self._tr_help,
                ESC_HELP2  : self._tr_help,
                ESC_MAGIC  : self._tr_magic,
                ESC_QUOTE  : self._tr_quote,
                ESC_QUOTE2 : self._tr_quote2,
                ESC_PAREN  : self._tr_paren }
         self.tr = tr
         
     # Support for syntax transformations that use explicit escapes typed by the
     # user at the beginning of a line
     @staticmethod
     def _tr_system(line_info):
         "Translate lines escaped with: !"
         cmd = line_info.line.lstrip().lstrip(ESC_SHELL)
         return '%sget_ipython().system(%s)' % (line_info.lspace,
                                                make_quoted_expr(cmd))
 
     @staticmethod
     def _tr_system2(line_info):
         "Translate lines escaped with: !!"
         cmd = line_info.line.lstrip()[2:]
         return '%sget_ipython().getoutput(%s)' % (line_info.lspace,
                                                   make_quoted_expr(cmd))
 
     @staticmethod
     def _tr_help(line_info):
         "Translate lines escaped with: ?/??"
         # A naked help line should just fire the intro help screen
         if not line_info.line[1:]:
             return 'get_ipython().show_usage()'
         
         return _make_help_call(line_info.fpart, line_info.esc, line_info.lspace)
 
     @staticmethod
     def _tr_magic(line_info):
         "Translate lines escaped with: %"
         tpl = '%sget_ipython().magic(%s)'
         cmd = make_quoted_expr(' '.join([line_info.fpart,
                                          line_info.rest]).strip())
         return tpl % (line_info.lspace, cmd)
 
     @staticmethod
     def _tr_quote(line_info):
         "Translate lines escaped with: ,"
         return '%s%s("%s")' % (line_info.lspace, line_info.fpart,
                              '", "'.join(line_info.rest.split()) )
 
     @staticmethod
     def _tr_quote2(line_info):
         "Translate lines escaped with: ;"
         return '%s%s("%s")' % (line_info.lspace, line_info.fpart,
                                line_info.rest)
 
     @staticmethod
     def _tr_paren(line_info):
         "Translate lines escaped with: /"
         return '%s%s(%s)' % (line_info.lspace, line_info.fpart,
                              ", ".join(line_info.rest.split()))
 
     def __call__(self, line):
         """Class to transform lines that are explicitly escaped out.
 
         This calls the above _tr_* static methods for the actual line
         translations."""
 
         # Empty lines just get returned unmodified
         if not line or line.isspace():
             return line
 
         # Get line endpoints, where the escapes can be
         line_info = LineInfo(line)
 
         if not line_info.esc in self.tr:
             # If we don't recognize the escape, don't modify the line
             return line
 
         return self.tr[line_info.esc](line_info)
 
 
 # A function-looking object to be used by the rest of the code.  The purpose of
 # the class in this case is to organize related functionality, more than to
 # manage state.
 transform_escaped = EscapedTransformer()
 
 
 class IPythonInputSplitter(InputSplitter):
     """An input splitter that recognizes all of IPython's special syntax."""
 
     # String with raw, untransformed input.
     source_raw = ''
 
     # Private attributes
     
     # List with lines of raw input accumulated so far.
     _buffer_raw = None
 
     def __init__(self, input_mode=None):
         InputSplitter.__init__(self, input_mode)
         self._buffer_raw = []
         
     def reset(self):
         """Reset the input buffer and associated state."""
         InputSplitter.reset(self)
         self._buffer_raw[:] = []
         self.source_raw = ''
 
     def source_raw_reset(self):
         """Return input and raw source and perform a full reset.
         """
         out = self.source
         out_r = self.source_raw
         self.reset()
         return out, out_r
 
     def push(self, lines):
         """Push one or more lines of IPython input.
         """
         if not lines:
             return super(IPythonInputSplitter, self).push(lines)
 
         # We must ensure all input is pure unicode
-        if type(lines)==str:
-            lines = lines.decode(self.encoding)
+        lines = cast_unicode(lines, self.encoding)
 
         lines_list = lines.splitlines()
 
         transforms = [transform_ipy_prompt, transform_classic_prompt,
                       transform_escaped, transform_help_end,
                       transform_assign_system, transform_assign_magic]
 
         # Transform logic
         #
         # We only apply the line transformers to the input if we have either no
         # input yet, or complete input, or if the last line of the buffer ends
         # with ':' (opening an indented block).  This prevents the accidental
         # transformation of escapes inside multiline expressions like
         # triple-quoted strings or parenthesized expressions.
         #
         # The last heuristic, while ugly, ensures that the first line of an
         # indented block is correctly transformed.
         #
         # FIXME: try to find a cleaner approach for this last bit.
 
         # If we were in 'block' mode, since we're going to pump the parent
         # class by hand line by line, we need to temporarily switch out to
         # 'line' mode, do a single manual reset and then feed the lines one
         # by one.  Note that this only matters if the input has more than one
         # line.
         changed_input_mode = False
 
         if self.input_mode == 'cell':
             self.reset()
             changed_input_mode = True
             saved_input_mode = 'cell'
             self.input_mode = 'line'
 
         # Store raw source before applying any transformations to it.  Note
         # that this must be done *after* the reset() call that would otherwise
         # flush the buffer.
         self._store(lines, self._buffer_raw, 'source_raw')
         
         try:
             push = super(IPythonInputSplitter, self).push
             for line in lines_list:
                 if self._is_complete or not self._buffer or \
                    (self._buffer and self._buffer[-1].rstrip().endswith(':')):
                     for f in transforms:
                         line = f(line)
 
                 out = push(line)
         finally:
             if changed_input_mode:
                 self.input_mode = saved_input_mode
         return out