text: # -*- coding: utf-8 -*-
  """Top-level display functions for displaying object in different formats."""
  
  # Copyright (c) IPython Development Team.
  # Distributed under the terms of the Modified BSD License.
  
  
  try:
      from base64 import encodebytes as base64_encode
  except ImportError:
      from base64 import encodestring as base64_encode
  
  from binascii import b2a_hex
  import json
  import mimetypes
  import os
  import struct
  import sys
  import warnings
  
  from IPython.utils.py3compat import cast_unicode
  from IPython.testing.skipdoctest import skip_doctest
  
  __all__ = ['display', 'display_pretty', 'display_html', 'display_markdown',
  'display_svg', 'display_png', 'display_jpeg', 'display_latex', 'display_json',
  'display_javascript', 'display_pdf', 'DisplayObject', 'TextDisplayObject',
  'Pretty', 'HTML', 'Markdown', 'Math', 'Latex', 'SVG', 'JSON', 'GeoJSON', 'Javascript',
  'Image', 'clear_output', 'set_matplotlib_formats', 'set_matplotlib_close',
  'publish_display_data', 'update_display', 'DisplayHandle', 'Video']
  
  #-----------------------------------------------------------------------------
  # utility functions
  #-----------------------------------------------------------------------------
  
  def _safe_exists(path):
      """Check path, but don't let exceptions raise"""
      try:
          return os.path.exists(path)
      except Exception:
          return False
  
  def _merge(d1, d2):
      """Like update, but merges sub-dicts instead of clobbering at the top level.
  
      Updates d1 in-place
      """
  
      if not isinstance(d2, dict) or not isinstance(d1, dict):
          return d2
      for key, value in d2.items():
          d1[key] = _merge(d1.get(key), value)
      return d1
  
  def _display_mimetype(mimetype, objs, raw=False, metadata=None):
      """internal implementation of all display_foo methods
  
      Parameters
      ----------
      mimetype : str
          The mimetype to be published (e.g. 'image/png')
      objs : tuple of objects
          The Python objects to display, or if raw=True raw text data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      if metadata:
          metadata = {mimetype: metadata}
      if raw:
          # turn list of pngdata into list of { 'image/png': pngdata }
          objs = [ {mimetype: obj} for obj in objs ]
      display(*objs, raw=raw, metadata=metadata, include=[mimetype])
  
  #-----------------------------------------------------------------------------
  # Main functions
  #-----------------------------------------------------------------------------
  
  # use * to indicate transient is keyword-only
  def publish_display_data(data, metadata=None, source=None, *, transient=None, **kwargs):
      """Publish data and metadata to all frontends.
  
      See the ``display_data`` message in the messaging documentation for
      more details about this message type.
  
      The following MIME types are currently implemented:
  
      * text/plain
      * text/html
      * text/markdown
      * text/latex
      * application/json
      * application/javascript
      * image/png
      * image/jpeg
      * image/svg+xml
  
      Parameters
      ----------
      data : dict
          A dictionary having keys that are valid MIME types (like
          'text/plain' or 'image/svg+xml') and values that are the data for
          that MIME type. The data itself must be a JSON'able data
          structure. Minimally all data should have the 'text/plain' data,
          which can be displayed by all frontends. If more than the plain
          text is given, it is up to the frontend to decide which
          representation to use.
      metadata : dict
          A dictionary for metadata related to the data. This can contain
          arbitrary key, value pairs that frontends can use to interpret
          the data. mime-type keys matching those in data can be used
          to specify metadata about particular representations.
      source : str, deprecated
          Unused.
      transient : dict, keyword-only
          A dictionary of transient data, such as display_id.
          """
      from IPython.core.interactiveshell import InteractiveShell
  
      display_pub = InteractiveShell.instance().display_pub
  
      # only pass transient if supplied,
      # to avoid errors with older ipykernel.
      # TODO: We could check for ipykernel version and provide a detailed upgrade message.
      if transient:
          kwargs['transient'] = transient
  
      display_pub.publish(
          data=data,
          metadata=metadata,
          **kwargs
      )
  
  
  def _new_id():
      """Generate a new random text id with urandom"""
      return b2a_hex(os.urandom(16)).decode('ascii')
  
  
  def display(*objs, include=None, exclude=None, metadata=None, transient=None, display_id=None, **kwargs):
      """Display a Python object in all frontends.
  
      By default all representations will be computed and sent to the frontends.
      Frontends can decide which representation is used and how.
  
      In terminal IPython this will be similar to using :func:`print`, for use in richer
      frontends see Jupyter notebook examples with rich display logic.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display.
      raw : bool, optional
          Are the objects to be displayed already mimetype-keyed dicts of raw display data,
          or Python objects that need to be formatted before display? [default: False]
      include : list, tuple or set, 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, tuple or set, optional
          A list of format type strings (MIME types) to exclude in the format
          data dict. If this is set all format types will be computed,
          except for those included in this argument.
      metadata : dict, optional
          A dictionary of metadata to associate with the output.
          mime-type keys in this dictionary will be associated with the individual
          representation formats, if they exist.
      transient : dict, optional
          A dictionary of transient data to associate with the output.
          Data in this dict should not be persisted to files (e.g. notebooks).
      display_id : str, bool optional
          Set an id for the display.
          This id can be used for updating this display area later via update_display.
          If given as `True`, generate a new `display_id`
      kwargs: additional keyword-args, optional
          Additional keyword-arguments are passed through to the display publisher.
  
      Returns
      -------
  
      handle: DisplayHandle
          Returns a handle on updatable displays for use with :func:`update_display`,
          if `display_id` is given. Returns :any:`None` if no `display_id` is given
          (default).
  
      Examples
      --------
  
      >>> class Json(object):
      ...     def __init__(self, json):
      ...         self.json = json
      ...     def _repr_pretty_(self, pp, cycle):
      ...         import json
      ...         pp.text(json.dumps(self.json, indent=2))
      ...     def __repr__(self):
      ...         return str(self.json)
      ...
  
      >>> d = Json({1:2, 3: {4:5}})
  
      >>> print(d)
      {1: 2, 3: {4: 5}}
  
      >>> display(d)
      {
        "1": 2,
        "3": {
          "4": 5
        }
      }
  
      >>> def int_formatter(integer, pp, cycle):
      ...     pp.text('I'*integer)
  
      >>> plain = get_ipython().display_formatter.formatters['text/plain']
      >>> plain.for_type(int, int_formatter)
      <function _repr_pprint at 0x...>
      >>> display(7-5)
      II
  
      >>> del plain.type_printers[int]
      >>> display(7-5)
      2
  
      See Also
      --------
  
      :func:`update_display`
  
      Notes
      -----
  
      In Python, objects can declare their textual representation using the
      `__repr__` method. IPython expands on this idea and allows objects to declare
      other, rich representations including:
  
        - HTML
        - JSON
        - PNG
        - JPEG
        - SVG
        - LaTeX
  
      A single object can declare some or all of these representations; all are
      handled by IPython's display system.
  
      The main idea of the first approach is that you have to implement special
      display methods when you define your class, one for each representation you
      want to use. Here is a list of the names of the special methods and the
      values they must return:
  
        - `_repr_html_`: return raw HTML as a string
        - `_repr_json_`: return a JSONable dict
        - `_repr_jpeg_`: return raw JPEG data
        - `_repr_png_`: return raw PNG data
        - `_repr_svg_`: return raw SVG data as a string
        - `_repr_latex_`: return LaTeX commands in a string surrounded by "$".
        - `_repr_mimebundle_`: return a full mimebundle containing the mapping
        from all mimetypes to data
  
      When you are directly writing your own classes, you can adapt them for
      display in IPython by following the above approach. But in practice, you
      often need to work with existing classes that you can't easily modify.
  
      You can refer to the documentation on IPython display formatters in order to
      register custom formatters for already existing types.
  
      .. versionadded:: 5.4 display available without import
      .. versionadded:: 6.1 display available without import
  
      Since IPython 5.4 and 6.1 :func:`display` is automatically made available to
      the user without import. If you are using display in a document that might
      be used in a pure python context or with older version of IPython, use the
      following import at the top of your file::
  
          from IPython.display import display
  
      """
      raw = kwargs.pop('raw', False)
      if transient is None:
          transient = {}
      if display_id:
          if display_id is True:
              display_id = _new_id()
          transient['display_id'] = display_id
      if kwargs.get('update') and 'display_id' not in transient:
          raise TypeError('display_id required for update_display')
      if transient:
          kwargs['transient'] = transient
  
      from IPython.core.interactiveshell import InteractiveShell
  
      if not raw:
          format = InteractiveShell.instance().display_formatter.format
  
      for obj in objs:
          if raw:
              publish_display_data(data=obj, metadata=metadata, **kwargs)
          else:
              format_dict, md_dict = format(obj, include=include, exclude=exclude)
              if not format_dict:
                  # nothing to display (e.g. _ipython_display_ took over)
                  continue
              if metadata:
                  # kwarg-specified metadata gets precedence
                  _merge(md_dict, metadata)
              publish_display_data(data=format_dict, metadata=md_dict, **kwargs)
      if display_id:
          return DisplayHandle(display_id)
  
  
  # use * for keyword-only display_id arg
  def update_display(obj, *, display_id, **kwargs):
      """Update an existing display by id
  
      Parameters
      ----------
  
      obj:
          The object with which to update the display
      display_id: keyword-only
          The id of the display to update
  
      See Also
      --------
  
      :func:`display`
      """
      kwargs['update'] = True
      display(obj, display_id=display_id, **kwargs)
  
  
  class DisplayHandle(object):
      """A handle on an updatable display
  
      Call `.update(obj)` to display a new object.
  
      Call `.display(obj`) to add a new instance of this display,
      and update existing instances.
  
      See Also
      --------
  
          :func:`display`, :func:`update_display`
  
      """
  
      def __init__(self, display_id=None):
          if display_id is None:
              display_id = _new_id()
          self.display_id = display_id
  
      def __repr__(self):
          return "<%s display_id=%s>" % (self.__class__.__name__, self.display_id)
  
      def display(self, obj, **kwargs):
          """Make a new display with my id, updating existing instances.
          
          Parameters
          ----------
          
          obj:
              object to display
          **kwargs:
              additional keyword arguments passed to display
          """
          display(obj, display_id=self.display_id, **kwargs)
  
      def update(self, obj, **kwargs):
          """Update existing displays with my id
          
          Parameters
          ----------
          
          obj:
              object to display
          **kwargs:
              additional keyword arguments passed to update_display
          """
          update_display(obj, display_id=self.display_id, **kwargs)
  
  
  def display_pretty(*objs, **kwargs):
      """Display the pretty (default) representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw text data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('text/plain', objs, **kwargs)
  
  
  def display_html(*objs, **kwargs):
      """Display the HTML representation of an object.
  
      Note: If raw=False and the object does not have a HTML
      representation, no HTML will be shown.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw HTML data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('text/html', objs, **kwargs)
  
  
  def display_markdown(*objs, **kwargs):
      """Displays the Markdown representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw markdown data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
  
      _display_mimetype('text/markdown', objs, **kwargs)
  
  
  def display_svg(*objs, **kwargs):
      """Display the SVG representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw svg data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('image/svg+xml', objs, **kwargs)
  
  
  def display_png(*objs, **kwargs):
      """Display the PNG representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw png data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('image/png', objs, **kwargs)
  
  
  def display_jpeg(*objs, **kwargs):
      """Display the JPEG representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw JPEG data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('image/jpeg', objs, **kwargs)
  
  
  def display_latex(*objs, **kwargs):
      """Display the LaTeX representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw latex data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('text/latex', objs, **kwargs)
  
  
  def display_json(*objs, **kwargs):
      """Display the JSON representation of an object.
  
      Note that not many frontends support displaying JSON.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw json data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('application/json', objs, **kwargs)
  
  
  def display_javascript(*objs, **kwargs):
      """Display the Javascript representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw javascript data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('application/javascript', objs, **kwargs)
  
  
  def display_pdf(*objs, **kwargs):
      """Display the PDF representation of an object.
  
      Parameters
      ----------
      objs : tuple of objects
          The Python objects to display, or if raw=True raw javascript data to
          display.
      raw : bool
          Are the data objects raw data or Python objects that need to be
          formatted before display? [default: False]
      metadata : dict (optional)
          Metadata to be associated with the specific mimetype output.
      """
      _display_mimetype('application/pdf', objs, **kwargs)
  
  
  #-----------------------------------------------------------------------------
  # Smart classes
  #-----------------------------------------------------------------------------
  
  
  class DisplayObject(object):
      """An object that wraps data to be displayed."""
  
      _read_flags = 'r'
      _show_mem_addr = False
  
      def __init__(self, data=None, url=None, filename=None):
          """Create a display object given raw data.
  
          When this object is returned by an expression or passed to the
          display function, it will result in the data being displayed
          in the frontend. The MIME type of the data should match the
          subclasses used, so the Png subclass should be used for 'image/png'
          data. If the data is a URL, the data will first be downloaded
          and then displayed. If
  
          Parameters
          ----------
          data : unicode, str or bytes
              The raw data or a URL or file to load the data from
          url : unicode
              A URL to download the data from.
          filename : unicode
              Path to a local file to load the data from.
          """
          if data is not None and isinstance(data, str):
              if data.startswith('http') and url is None:
                  url = data
                  filename = None
                  data = None
              elif _safe_exists(data) and filename is None:
                  url = None
                  filename = data
                  data = None
  
          self.data = data
          self.url = url
          self.filename = filename
  
          self.reload()
          self._check_data()
  
      def __repr__(self):
          if not self._show_mem_addr:
              cls = self.__class__
              r = "<%s.%s object>" % (cls.__module__, cls.__name__)
          else:
              r = super(DisplayObject, self).__repr__()
          return r
  
      def _check_data(self):
          """Override in subclasses if there's something to check."""
          pass
  
      def reload(self):
          """Reload the raw data from file or URL."""
          if self.filename is not None:
              with open(self.filename, self._read_flags) as f:
                  self.data = f.read()
          elif self.url is not None:
              try:
                  # Deferred import
                  from urllib.request import urlopen
                  response = urlopen(self.url)
                  self.data = response.read()
                  # extract encoding from header, if there is one:
                  encoding = None
                  for sub in response.headers['content-type'].split(';'):
                      sub = sub.strip()
                      if sub.startswith('charset'):
                          encoding = sub.split('=')[-1].strip()
                          break
                  # decode data, if an encoding was specified
                  if encoding:
                      self.data = self.data.decode(encoding, 'replace')
              except:
                  self.data = None
  
  class TextDisplayObject(DisplayObject):
      """Validate that display data is text"""
      def _check_data(self):
          if self.data is not None and not isinstance(self.data, str):
              raise TypeError("%s expects text, not %r" % (self.__class__.__name__, self.data))
  
  class Pretty(TextDisplayObject):
  
      def _repr_pretty_(self):
          return self.data
  
  
  class HTML(TextDisplayObject):
  
      def _repr_html_(self):
          return self.data
  
      def __html__(self):
          """
          This method exists to inform other HTML-using modules (e.g. Markupsafe,
          htmltag, etc) that this object is HTML and does not need things like
          special characters (<>&) escaped.
          """
          return self._repr_html_()
  
  
  class Markdown(TextDisplayObject):
  
      def _repr_markdown_(self):
          return self.data
  
  
  class Math(TextDisplayObject):
  
      def _repr_latex_(self):
          s = self.data.strip('$')
          return "$$%s$$" % s
  
  
  class Latex(TextDisplayObject):
  
      def _repr_latex_(self):
          return self.data
  
  
  class SVG(DisplayObject):
  
      _read_flags = 'rb'
      # wrap data in a property, which extracts the <svg> tag, discarding
      # document headers
      _data = None
  
      @property
      def data(self):
          return self._data
  
      @data.setter
      def data(self, svg):
          if svg is None:
              self._data = None
              return
          # parse into dom object
          from xml.dom import minidom
          x = minidom.parseString(svg)
          # get svg tag (should be 1)
          found_svg = x.getElementsByTagName('svg')
          if found_svg:
              svg = found_svg[0].toxml()
          else:
              # fallback on the input, trust the user
              # but this is probably an error.
              pass
          svg = cast_unicode(svg)
          self._data = svg
  
      def _repr_svg_(self):
          return self.data
  
  
  class JSON(DisplayObject):
      """JSON expects a JSON-able dict or list
  
      not an already-serialized JSON string.
  
      Scalar types (None, number, string) are not allowed, only dict or list containers.
      """
      # wrap data in a property, which warns about passing already-serialized JSON
      _data = None
      def __init__(self, data=None, url=None, filename=None, expanded=False, metadata=None, **kwargs):
          """Create a JSON display object given raw data.
  
          Parameters
          ----------
          data : dict or list
              JSON data to display. Not an already-serialized JSON string.
              Scalar types (None, number, string) are not allowed, only dict
              or list containers.
          url : unicode
              A URL to download the data from.
          filename : unicode
              Path to a local file to load the data from.
          expanded : boolean
              Metadata to control whether a JSON display component is expanded.
          metadata: dict
              Specify extra metadata to attach to the json display object.
          """
          self.metadata = {'expanded': expanded}
          if metadata:
              self.metadata.update(metadata)
          if kwargs:
              self.metadata.update(kwargs)
          super(JSON, self).__init__(data=data, url=url, filename=filename)
  
      def _check_data(self):
          if self.data is not None and not isinstance(self.data, (dict, list)):
              raise TypeError("%s expects JSONable dict or list, not %r" % (self.__class__.__name__, self.data))
  
      @property
      def data(self):
          return self._data
  
      @data.setter
      def data(self, data):
          if isinstance(data, str):
              if getattr(self, 'filename', None) is None:
                  warnings.warn("JSON expects JSONable dict or list, not JSON strings")
              data = json.loads(data)
          self._data = data
  
      def _data_and_metadata(self):
          return self.data, self.metadata
  
      def _repr_json_(self):
          return self._data_and_metadata()
  
  _css_t = """$("head").append($("<link/>").attr({
    rel:  "stylesheet",
    type: "text/css",
    href: "%s"
  }));
  """
  
  _lib_t1 = """$.getScript("%s", function () {
  """
  _lib_t2 = """});
  """
  
  class GeoJSON(JSON):
      """GeoJSON expects JSON-able dict
  
      not an already-serialized JSON string.
  
      Scalar types (None, number, string) are not allowed, only dict containers.
      """
      
      def __init__(self, *args, **kwargs):
          """Create a GeoJSON display object given raw data.
  
          Parameters
          ----------
          data : dict or list
              VegaLite data. Not an already-serialized JSON string.
              Scalar types (None, number, string) are not allowed, only dict
              or list containers.
          url_template : string
              Leaflet TileLayer URL template: http://leafletjs.com/reference.html#url-template
          layer_options : dict
              Leaflet TileLayer options: http://leafletjs.com/reference.html#tilelayer-options
          url : unicode
              A URL to download the data from.
          filename : unicode
              Path to a local file to load the data from.
          metadata: dict
              Specify extra metadata to attach to the json display object.
  
          Examples
          --------
  
          The following will display an interactive map of Mars with a point of
          interest on frontend that do support GeoJSON display.
  
              >>> from IPython.display import GeoJSON
  
              >>> GeoJSON(data={
              ...     "type": "Feature",
              ...     "geometry": {
              ...         "type": "Point",
              ...         "coordinates": [-81.327, 296.038]
              ...     }
              ... },
              ... url_template="http://s3-eu-west-1.amazonaws.com/whereonmars.cartodb.net/{basemap_id}/{z}/{x}/{y}.png",
              ... layer_options={
              ...     "basemap_id": "celestia_mars-shaded-16k_global",
              ...     "attribution" : "Celestia/praesepe",
              ...     "minZoom" : 0,
              ...     "maxZoom" : 18,
              ... })
              <IPython.core.display.GeoJSON object>
  
          In the terminal IPython, you will only see the text representation of
          the GeoJSON object.
  
          """
          
          super(GeoJSON, self).__init__(*args, **kwargs)
  
  
      def _ipython_display_(self):
          bundle = {
              'application/geo+json': self.data,
              'text/plain': '<IPython.display.GeoJSON object>'
          }
          metadata = {
              'application/geo+json': self.metadata
          }
          display(bundle, metadata=metadata, raw=True)
  
  class Javascript(TextDisplayObject):
  
      def __init__(self, data=None, url=None, filename=None, lib=None, css=None):
          """Create a Javascript display object given raw data.
  
          When this object is returned by an expression or passed to the
          display function, it will result in the data being displayed
          in the frontend. If the data is a URL, the data will first be
          downloaded and then displayed.
  
          In the Notebook, the containing element will be available as `element`,
          and jQuery will be available.  Content appended to `element` will be
          visible in the output area.
  
          Parameters
          ----------
          data : unicode, str or bytes
              The Javascript source code or a URL to download it from.
          url : unicode
              A URL to download the data from.
          filename : unicode
              Path to a local file to load the data from.
          lib : list or str
              A sequence of Javascript library URLs to load asynchronously before
              running the source code. The full URLs of the libraries should
              be given. A single Javascript library URL can also be given as a
              string.
          css: : list or str
              A sequence of css files to load before running the source code.
              The full URLs of the css files should be given. A single css URL
              can also be given as a string.
          """
          if isinstance(lib, str):
              lib = [lib]
          elif lib is None:
              lib = []
          if isinstance(css, str):
              css = [css]
          elif css is None:
              css = []
          if not isinstance(lib, (list,tuple)):
              raise TypeError('expected sequence, got: %r' % lib)
          if not isinstance(css, (list,tuple)):
              raise TypeError('expected sequence, got: %r' % css)
          self.lib = lib
          self.css = css
          super(Javascript, self).__init__(data=data, url=url, filename=filename)
  
      def _repr_javascript_(self):
          r = ''
          for c in self.css:
              r += _css_t % c
          for l in self.lib:
              r += _lib_t1 % l
          r += self.data
          r += _lib_t2*len(self.lib)
          return r
  
  # constants for identifying png/jpeg data
  _PNG = b'\x89PNG\r\n\x1a\n'
  _JPEG = b'\xff\xd8'
  
  def _pngxy(data):
      """read the (width, height) from a PNG header"""
      ihdr = data.index(b'IHDR')
      # next 8 bytes are width/height
      w4h4 = data[ihdr+4:ihdr+12]
      return struct.unpack('>ii', w4h4)
  
  def _jpegxy(data):
      """read the (width, height) from a JPEG header"""
      # adapted from http://www.64lines.com/jpeg-width-height
  
      idx = 4
      while True:
          block_size = struct.unpack('>H', data[idx:idx+2])[0]
          idx = idx + block_size
          if data[idx:idx+2] == b'\xFF\xC0':
              # found Start of Frame
              iSOF = idx
              break
          else:
              # read another block
              idx += 2
  
      h, w = struct.unpack('>HH', data[iSOF+5:iSOF+9])
      return w, h
  
  class Image(DisplayObject):
  
      _read_flags = 'rb'
      _FMT_JPEG = u'jpeg'
      _FMT_PNG = u'png'
      _ACCEPTABLE_EMBEDDINGS = [_FMT_JPEG, _FMT_PNG]
  
      def __init__(self, data=None, url=None, filename=None, format=None,
                   embed=None, width=None, height=None, retina=False,
                   unconfined=False, metadata=None):
          """Create a PNG/JPEG image object given raw data.
  
          When this object is returned by an input cell or passed to the
          display function, it will result in the image being displayed
          in the frontend.
  
          Parameters
          ----------
          data : unicode, str or bytes
              The raw image data or a URL or filename to load the data from.
              This always results in embedded image data.
          url : unicode
              A URL to download the data from. If you specify `url=`,
              the image data will not be embedded unless you also specify `embed=True`.
          filename : unicode
              Path to a local file to load the data from.
              Images from a file are always embedded.
          format : unicode
              The format of the image data (png/jpeg/jpg). If a filename or URL is given
              for format will be inferred from the filename extension.
          embed : bool
              Should the image data be embedded using a data URI (True) or be
              loaded using an <img> tag. Set this to True if you want the image
              to be viewable later with no internet connection in the notebook.
  
              Default is `True`, unless the keyword argument `url` is set, then
              default value is `False`.
  
              Note that QtConsole is not able to display images if `embed` is set to `False`
          width : int
              Width in pixels to which to constrain the image in html
          height : int
              Height in pixels to which to constrain the image in html
          retina : bool
              Automatically set the width and height to half of the measured
              width and height.
              This only works for embedded images because it reads the width/height
              from image data.
              For non-embedded images, you can just set the desired display width
              and height directly.
          unconfined: bool
              Set unconfined=True to disable max-width confinement of the image.
          metadata: dict
              Specify extra metadata to attach to the image.
  
          Examples
          --------
          # embedded image data, works in qtconsole and notebook
          # when passed positionally, the first arg can be any of raw image data,
          # a URL, or a filename from which to load image data.
          # The result is always embedding image data for inline images.
          Image('http://www.google.fr/images/srpr/logo3w.png')
          Image('/path/to/image.jpg')
          Image(b'RAW_PNG_DATA...')
  
          # Specifying Image(url=...) does not embed the image data,
          # it only generates `<img>` tag with a link to the source.
          # This will not work in the qtconsole or offline.
          Image(url='http://www.google.fr/images/srpr/logo3w.png')
  
          """
          if filename is not None:
              ext = self._find_ext(filename)
          elif url is not None:
              ext = self._find_ext(url)
          elif data is None:
              raise ValueError("No image data found. Expecting filename, url, or data.")
          elif isinstance(data, str) and (
              data.startswith('http') or _safe_exists(data)
          ):
              ext = self._find_ext(data)
          else:
              ext = None
  
          if format is None:
              if ext is not None:
                  if ext == u'jpg' or ext == u'jpeg':
                      format = self._FMT_JPEG
                  if ext == u'png':
                      format = self._FMT_PNG
                  else:
                      format = ext.lower()
              elif isinstance(data, bytes):
                  # infer image type from image data header,
                  # only if format has not been specified.
                  if data[:2] == _JPEG:
                      format = self._FMT_JPEG
  
          # failed to detect format, default png
          if format is None:
              format = 'png'
  
          if format.lower() == 'jpg':
              # jpg->jpeg
              format = self._FMT_JPEG
  
          self.format = format.lower()
          self.embed = embed if embed is not None else (url is None)
  
          if self.embed and self.format not in self._ACCEPTABLE_EMBEDDINGS:
              raise ValueError("Cannot embed the '%s' image format" % (self.format))
          self.width = width
          self.height = height
          self.retina = retina
          self.unconfined = unconfined
          self.metadata = metadata
          super(Image, self).__init__(data=data, url=url, filename=filename)
  
          if retina:
              self._retina_shape()
  
      def _retina_shape(self):
          """load pixel-doubled width and height from image data"""
          if not self.embed:
              return
          if self.format == 'png':
              w, h = _pngxy(self.data)
          elif self.format == 'jpeg':
              w, h = _jpegxy(self.data)
          else:
              # retina only supports png
              return
          self.width = w // 2
          self.height = h // 2
  
      def reload(self):
          """Reload the raw data from file or URL."""
          if self.embed:
              super(Image,self).reload()
              if self.retina:
                  self._retina_shape()
  
      def _repr_html_(self):
          if not self.embed:
              width = height = klass = ''
              if self.width:
                  width = ' width="%d"' % self.width
              if self.height:
                  height = ' height="%d"' % self.height
              if self.unconfined:
                  klass = ' class="unconfined"'
              return u'<img src="{url}"{width}{height}{klass}/>'.format(
                  url=self.url,
                  width=width,
                  height=height,
                  klass=klass,
              )
  
      def _data_and_metadata(self):
          """shortcut for returning metadata with shape information, if defined"""
          md = {}
          if self.width:
              md['width'] = self.width
          if self.height:
              md['height'] = self.height
          if self.unconfined:
              md['unconfined'] = self.unconfined
          if self.metadata:
              md.update(self.metadata)
          if md:
              return self.data, md
          else:
              return self.data
  
      def _repr_png_(self):
          if self.embed and self.format == u'png':
              return self._data_and_metadata()
  
      def _repr_jpeg_(self):
          if self.embed and (self.format == u'jpeg' or self.format == u'jpg'):
              return self._data_and_metadata()
  
      def _find_ext(self, s):
          return s.split('.')[-1].lower()
  
  class Video(DisplayObject):
  
      def __init__(self, data=None, url=None, filename=None, embed=False, mimetype=None):
          """Create a video object given raw data or an URL.
  
          When this object is returned by an input cell or passed to the
          display function, it will result in the video being displayed
          in the frontend.
  
          Parameters
          ----------
          data : unicode, str or bytes
              The raw video data or a URL or filename to load the data from.
              Raw data will require passing `embed=True`.
          url : unicode
              A URL for the video. If you specify `url=`,
              the image data will not be embedded.
          filename : unicode
              Path to a local file containing the video.
              Will be interpreted as a local URL unless `embed=True`.
          embed : bool
              Should the video be embedded using a data URI (True) or be
              loaded using a <video> tag (False).
  
              Since videos are large, embedding them should be avoided, if possible.
              You must confirm embedding as your intention by passing `embed=True`.
  
              Local files can be displayed with URLs without embedding the content, via::
  
                  Video('./video.mp4')
  
          mimetype: unicode
              Specify the mimetype for embedded videos.
              Default will be guessed from file extension, if available.
  
          Examples
          --------
  
          Video('https://archive.org/download/Sita_Sings_the_Blues/Sita_Sings_the_Blues_small.mp4')
          Video('path/to/video.mp4')
          Video('path/to/video.mp4', embed=True)
          Video(b'raw-videodata', embed=True)
          """
          if url is None and isinstance(data, str) and data.startswith(('http:', 'https:')):
              url = data
              data = None
          elif os.path.exists(data):
              filename = data
              data = None
  
          if data and not embed:
              msg = ''.join([
                  "To embed videos, you must pass embed=True ",
                  "(this may make your notebook files huge)\n",
                  "Consider passing Video(url='...')",
              ])
              raise ValueError(msg)
  
          self.mimetype = mimetype
          self.embed = embed
          super(Video, self).__init__(data=data, url=url, filename=filename)
  
      def _repr_html_(self):
          # External URLs and potentially local files are not embedded into the
          # notebook output.
          if not self.embed:
              url = self.url if self.url is not None else self.filename
              output = """<video src="{0}" controls>
        Your browser does not support the <code>video</code> element.
      </video>""".format(url)
              return output
  
          # Embedded videos are base64-encoded.
          mimetype = self.mimetype
          if self.filename is not None:
              if not mimetype:
                  mimetype, _ = mimetypes.guess_type(self.filename)
  
              with open(self.filename, 'rb') as f:
                  video = f.read()
          else:
              video = self.data
          if isinstance(video, str):
              # unicode input is already b64-encoded
              b64_video = video
          else:
              b64_video = base64_encode(video).decode('ascii').rstrip()
  
          output = """<video controls>
   <source src="data:{0};base64,{1}" type="{0}">
   Your browser does not support the video tag.
   </video>""".format(mimetype, b64_video)
          return output
  
      def reload(self):
          # TODO
          pass
  
      def _repr_png_(self):
          # TODO
          pass
      def _repr_jpeg_(self):
          # TODO
          pass
  
  def clear_output(wait=False):
      """Clear the output of the current cell receiving output.
  
      Parameters
      ----------
      wait : bool [default: false]
          Wait to clear the output until new output is available to replace it."""
      from IPython.core.interactiveshell import InteractiveShell
      if InteractiveShell.initialized():
          InteractiveShell.instance().display_pub.clear_output(wait)
      else:
          print('\033[2K\r', end='')
          sys.stdout.flush()
          print('\033[2K\r', end='')
          sys.stderr.flush()
  
  
  @skip_doctest
  def set_matplotlib_formats(*formats, **kwargs):
      """Select figure formats for the inline backend. Optionally pass quality for JPEG.
  
      For example, this enables PNG and JPEG output with a JPEG quality of 90%::
  
          In [1]: set_matplotlib_formats('png', 'jpeg', quality=90)
  
      To set this in your config files use the following::
  
          c.InlineBackend.figure_formats = {'png', 'jpeg'}
          c.InlineBackend.print_figure_kwargs.update({'quality' : 90})
  
      Parameters
      ----------
      *formats : strs
          One or more figure formats to enable: 'png', 'retina', 'jpeg', 'svg', 'pdf'.
      **kwargs :
          Keyword args will be relayed to ``figure.canvas.print_figure``.
      """
      from IPython.core.interactiveshell import InteractiveShell
      from IPython.core.pylabtools import select_figure_formats
      # build kwargs, starting with InlineBackend config
      kw = {}
      from ipykernel.pylab.config import InlineBackend
      cfg = InlineBackend.instance()
      kw.update(cfg.print_figure_kwargs)
      kw.update(**kwargs)
      shell = InteractiveShell.instance()
      select_figure_formats(shell, formats, **kw)
  
  @skip_doctest
  def set_matplotlib_close(close=True):
      """Set whether the inline backend closes all figures automatically or not.
  
      By default, the inline backend used in the IPython Notebook will close all
      matplotlib figures automatically after each cell is run. This means that
      plots in different cells won't interfere. Sometimes, you may want to make
      a plot in one cell and then refine it in later cells. This can be accomplished
      by::
  
          In [1]: set_matplotlib_close(False)
  
      To set this in your config files use the following::
  
          c.InlineBackend.close_figures = False
  
      Parameters
      ----------
      close : bool
          Should all matplotlib figures be automatically closed after each cell is
          run?
      """
      from ipykernel.pylab.config import InlineBackend
      cfg = InlineBackend.instance()
      cfg.close_figures = close
  