This file is indexed.

/usr/lib/python2.7/dist-packages/IPython/core/display.py is in python-ipython 5.1.0-3.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
# -*- 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.

from __future__ import print_function

try:
    from base64 import encodebytes as base64_encode
except ImportError:
    from base64 import encodestring as base64_encode

import json
import mimetypes
import os
import struct
import sys
import warnings

from IPython.utils.py3compat import (string_types, cast_bytes_py2, cast_unicode,
                                     unicode_type)
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', 'Javascript',
'Image', 'clear_output', 'set_matplotlib_formats', 'set_matplotlib_close',
'publish_display_data']

#-----------------------------------------------------------------------------
# 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
#-----------------------------------------------------------------------------

def publish_display_data(data, metadata=None, source=None):
    """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.
        """
    from IPython.core.interactiveshell import InteractiveShell
    InteractiveShell.instance().display_pub.publish(
        data=data,
        metadata=metadata,
    )

def display(*objs, **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.

    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 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 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.
    """
    raw = kwargs.get('raw', False)
    include = kwargs.get('include')
    exclude = kwargs.get('exclude')
    metadata = kwargs.get('metadata')

    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)
        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)


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, string_types):
            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 = None if filename is None else unicode_type(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:
                try:
                    from urllib.request import urlopen  # Py3
                except ImportError:
                    from urllib2 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, string_types):
            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):

    # 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
        svg = cast_bytes_py2(svg)
        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 _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, string_types):
            warnings.warn("JSON expects JSONable dict or list, not JSON strings")
            data = json.loads(data)
        self._data = data

    def _repr_json_(self):
        return self.data

css_t = """$("head").append($("<link/>").attr({
  rel:  "stylesheet",
  type: "text/css",
  href: "%s"
}));
"""

lib_t1 = """$.getScript("%s", function () {
"""
lib_t2 = """});
"""

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, string_types):
            lib = [lib]
        elif lib is None:
            lib = []
        if isinstance(css, string_types):
            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, string_types) 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 = unicode_type(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 unicode_type(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, string_types) 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, unicode_type):
            # 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