def test_Bug_2543():
    # Test that it possible to add all values to itself / deepcopy
    # This was not possible because validate_bool_maybe_none did not
    # accept None as an argument.
    # https://github.com/matplotlib/matplotlib/issues/2543
    # We filter warnings at this stage since a number of them are raised
    # for deprecated rcparams as they should. We dont want these in the
    # printed in the test suite.
    with warnings.catch_warnings():
        warnings.filterwarnings('ignore',
                                message='.*(deprecated|obsolete)',
                                category=UserWarning)
        with mpl.rc_context():
            _copy = mpl.rcParams.copy()
            for key in six.iterkeys(_copy):
                mpl.rcParams[key] = _copy[key]
            mpl.rcParams['text.dvipnghack'] = None
        with mpl.rc_context():
            from copy import deepcopy
            _deep_copy = deepcopy(mpl.rcParams)
        # real test is that this does not raise
        assert_true(validate_bool_maybe_none(None) is None)
        assert_true(validate_bool_maybe_none("none") is None)
        _fonttype = mpl.rcParams['svg.fonttype']
        assert_true(_fonttype == mpl.rcParams['svg.embed_char_paths'])
        with mpl.rc_context():
            mpl.rcParams['svg.embed_char_paths'] = False
            assert_true(mpl.rcParams['svg.fonttype'] == "none")

    def get_legend_handler(legend_handler_map, orig_handle):
        """
        return a legend handler from *legend_handler_map* that
        corresponds to *orig_handler*.

        *legend_handler_map* should be a dictionary object (that is
        returned by the get_legend_handler_map method).

        It first checks if the *orig_handle* itself is a key in the
        *legend_hanler_map* and return the associated value.
        Otherwise, it checks for each of the classes in its
        method-resolution-order. If no matching key is found, it
        returns None.
        """
        legend_handler_keys = list(six.iterkeys(legend_handler_map))
        if orig_handle in legend_handler_keys:
            handler = legend_handler_map[orig_handle]
        else:

            for handle_type in type(orig_handle).mro():
                if handle_type in legend_handler_map:
                    handler = legend_handler_map[handle_type]
                    break
            else:
                handler = None

        return handler

def comparable_formats():
    """
    Returns the list of file formats that compare_images can compare
    on this system.

    """
    return ['png'] + list(six.iterkeys(converter))

    def __init__(self, ax, loc=None, bbox=None, **kwargs):

        Artist.__init__(self)

        if is_string_like(loc) and loc not in self.codes:
            warnings.warn('Unrecognized location %s. Falling back on '
                          'bottom; valid locations are\n%s\t' %
                          (loc, '\n\t'.join(six.iterkeys(self.codes))))
            loc = 'bottom'
        if is_string_like(loc):
            loc = self.codes.get(loc, 1)
        self.set_figure(ax.figure)
        self._axes = ax
        self._loc = loc
        self._bbox = bbox

        # use axes coords
        self.set_transform(ax.transAxes)

        self._texts = []
        self._cells = {}
        self._edges = None
        self._autoRows = []
        self._autoColumns = []
        self._autoFontsize = True
        self.update(kwargs)

        self.set_clip_on(False)

        self._cachedRenderer = None

def validate_fonttype(s):
    """
    confirm that this is a Postscript of PDF font type that we know how to
    convert to
    """
    fonttypes = {"type3": 3, "truetype": 42}
    try:
        fonttype = validate_int(s)
    except ValueError:
        if s.lower() in six.iterkeys(fonttypes):
            return fonttypes[s.lower()]
        raise ValueError("Supported Postscript/PDF font types are %s" % list(six.iterkeys(fonttypes)))
    else:
        if fonttype not in six.itervalues(fonttypes):
            raise ValueError("Supported Postscript/PDF font types are %s" % list(six.itervalues(fonttypes)))
        return fonttype

   def __init__( self, frame, sec=None, jd=None, daynum=None, dt=None ):
      """Create a new Epoch object.

      Build an epoch 1 of 2 ways:

      Using seconds past a Julian date:
      #   Epoch( 'ET', sec=1e8, jd=2451545 )

      or using a matplotlib day number
      #   Epoch( 'ET', daynum=730119.5 )


      = ERROR CONDITIONS
      - If the input units are not in the allowed list, an error is thrown.

      = INPUT VARIABLES
      - frame    The frame of the epoch.  Must be 'ET' or 'UTC'
      - sec      The number of seconds past the input JD.
      - jd       The Julian date of the epoch.
      - daynum   The matplotlib day number of the epoch.
      - dt       A python datetime instance.
      """
      if ( ( sec is None and jd is not None ) or
           ( sec is not None and jd is None ) or
           ( daynum is not None and ( sec is not None or jd is not None ) ) or
           ( daynum is None and dt is None and ( sec is None or jd is None ) ) or
           ( daynum is not None and dt is not None ) or
           ( dt is not None and ( sec is not None or jd is not None ) ) or
           ( (dt is not None) and not isinstance(dt, DT.datetime) ) ):
         msg = "Invalid inputs.  Must enter sec and jd together, " \
               "daynum by itself, or dt (must be a python datetime).\n" \
               "Sec = %s\nJD  = %s\ndnum= %s\ndt  = %s" \
               % ( str( sec ), str( jd ), str( daynum ), str( dt ) )
         raise ValueError( msg )

      if frame not in self.allowed:
         msg = "Input frame '%s' is not one of the supported frames of %s" \
               % ( frame, str( list(six.iterkeys(self.allowed) ) ) )
         raise ValueError(msg)

      self._frame = frame

      if dt is not None:
         daynum = date2num( dt )

      if daynum is not None:
         # 1-JAN-0001 in JD = 1721425.5
         jd = float( daynum ) + 1721425.5
         self._jd = math.floor( jd )
         self._seconds = ( jd - self._jd ) * 86400.0

      else:
         self._seconds = float( sec )
         self._jd = float( jd )

         # Resolve seconds down to [ 0, 86400 )
         deltaDays = int( math.floor( self._seconds / 86400.0 ) )
         self._jd += deltaDays
         self._seconds -= deltaDays * 86400.0

 def get_projection_names(self):
     """
     Get a list of the names of all projections currently
     registered.
     """
     names = list(six.iterkeys(self._all_projection_types))
     names.sort()
     return names

    def _get_grid_bbox(self, renderer):
        """Get a bbox, in axes co-ordinates for the cells.

        Only include those in the range (0,0) to (maxRow, maxCol)"""
        boxes = [self._cells[pos].get_window_extent(renderer)
                 for pos in six.iterkeys(self._cells)
                 if pos[0] >= 0 and pos[1] >= 0]

        bbox = Bbox.union(boxes)
        return bbox.inverse_transformed(self.get_transform())

def test_colormap_reversing():
    """Check the generated _lut data of a colormap and corresponding
    reversed colormap if they are almost the same."""
    for name in six.iterkeys(cm.cmap_d):
        cmap = plt.get_cmap(name)
        cmap_r = cmap.reversed()
        if not cmap_r._isinit:
            cmap._init()
            cmap_r._init()
        assert_array_almost_equal(cmap._lut[:-3], cmap_r._lut[-4::-1])

 def __init__(self, scale, tfm, texname, vf):
     if six.PY3 and isinstance(texname, bytes):
         texname = texname.decode('ascii')
     self._scale, self._tfm, self.texname, self._vf = \
         scale, tfm, texname, vf
     self.size = scale * (72.0 / (72.27 * 2**16))
     try:
         nchars = max(six.iterkeys(tfm.width)) + 1
     except ValueError:
         nchars = 0
     self.widths = [(1000*tfm.width.get(char, 0)) >> 20
                    for char in xrange(nchars)]

   def checkUnits( self, units ):
      """Check to see if some units are valid.

      = ERROR CONDITIONS
      - If the input units are not in the allowed list, an error is thrown.

      = INPUT VARIABLES
      - units    The string name of the units to check.
      """
      if units not in self.allowed:
         msg = "Input units '%s' are not one of the supported types of %s" \
               % ( units, str( list(six.iterkeys(self.allowed)) ) )
         raise ValueError( msg )

    def aliased_name(self, s):
        """
        return 'PROPNAME or alias' if *s* has an alias, else return
        PROPNAME.

        e.g., for the line markerfacecolor property, which has an
        alias, return 'markerfacecolor or mfc' and for the transform
        property, which does not, return 'transform'
        """

        if s in self.aliasd:
            return s + "".join([" or %s" % x for x in six.iterkeys(self.aliasd[s])])
        else:
            return s

def test_RcParams_class():
    rc = mpl.RcParams(
        {
            "font.cursive": ["Apple Chancery", "Textile", "Zapf Chancery", "cursive"],
            "font.family": "sans-serif",
            "font.weight": "normal",
            "font.size": 12,
        }
    )

    if six.PY3:
        expected_repr = """
RcParams({'font.cursive': ['Apple Chancery',
                           'Textile',
                           'Zapf Chancery',
                           'cursive'],
          'font.family': ['sans-serif'],
          'font.size': 12.0,
          'font.weight': 'normal'})""".lstrip()
    else:
        expected_repr = """
RcParams({u'font.cursive': [u'Apple Chancery',
                            u'Textile',
                            u'Zapf Chancery',
                            u'cursive'],
          u'font.family': [u'sans-serif'],
          u'font.size': 12.0,
          u'font.weight': u'normal'})""".lstrip()

    assert_str_equal(expected_repr, repr(rc))

    if six.PY3:
        expected_str = """
font.cursive: ['Apple Chancery', 'Textile', 'Zapf Chancery', 'cursive']
font.family: ['sans-serif']
font.size: 12.0
font.weight: normal""".lstrip()
    else:
        expected_str = """
font.cursive: [u'Apple Chancery', u'Textile', u'Zapf Chancery', u'cursive']
font.family: [u'sans-serif']
font.size: 12.0
font.weight: normal""".lstrip()

    assert_str_equal(expected_str, str(rc))

    # test the find_all functionality
    assert ["font.cursive", "font.size"] == sorted(rc.find_all("i[vz]").keys())
    assert ["font.family"] == list(six.iterkeys(rc.find_all("family")))

    def _do_cell_alignment(self):
        """ Calculate row heights and column widths.

        Position cells accordingly.
        """
        # Calculate row/column widths
        widths = {}
        heights = {}
        for (row, col), cell in six.iteritems(self._cells):
            height = heights.setdefault(row, 0.0)
            heights[row] = max(height, cell.get_height())
            width = widths.setdefault(col, 0.0)
            widths[col] = max(width, cell.get_width())

        # work out left position for each column
        xpos = 0
        lefts = {}
        cols = list(six.iterkeys(widths))
        cols.sort()
        for col in cols:
            lefts[col] = xpos
            xpos += widths[col]

        ypos = 0
        bottoms = {}
        rows = list(six.iterkeys(heights))
        rows.sort()
        rows.reverse()
        for row in rows:
            bottoms[row] = ypos
            ypos += heights[row]

        # set cell positions
        for (row, col), cell in six.iteritems(self._cells):
            cell.set_x(lefts[col])
            cell.set_y(bottoms[row])

    def aliased_name_rest(self, s, target):
        """
        return 'PROPNAME or alias' if *s* has an alias, else return
        PROPNAME formatted for ReST

        e.g., for the line markerfacecolor property, which has an
        alias, return 'markerfacecolor or mfc' and for the transform
        property, which does not, return 'transform'
        """

        if s in self.aliasd:
            aliases = "".join([" or %s" % x for x in six.iterkeys(self.aliasd[s])])
        else:
            aliases = ""
        return ":meth:`%s <%s>`%s" % (s, target, aliases)

def win32InstalledFonts(directory=None, fontext="ttf"):
    """
    Search for fonts in the specified font directory, or use the
    system directories if none given.  A list of TrueType font
    filenames are returned by default, or AFM fonts if *fontext* ==
    'afm'.
    """

    from matplotlib.externals.six.moves import winreg

    if directory is None:
        directory = win32FontDirectory()

    fontext = get_fontext_synonyms(fontext)

    key, items = None, {}
    for fontdir in MSFontDirectories:
        try:
            local = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, fontdir)
        except OSError:
            continue

        if not local:
            return list_fonts(directory, fontext)
        try:
            for j in range(winreg.QueryInfoKey(local)[1]):
                try:
                    key, direc, any = winreg.EnumValue(local, j)
                    if not is_string_like(direc):
                        continue
                    if not os.path.dirname(direc):
                        direc = os.path.join(directory, direc)
                    direc = os.path.abspath(direc).lower()
                    if os.path.splitext(direc)[1][1:] in fontext:
                        items[direc] = 1
                except EnvironmentError:
                    continue
                except WindowsError:
                    continue
                except MemoryError:
                    continue
            return list(six.iterkeys(items))
        finally:
            winreg.CloseKey(local)
    return None

    def contains(self, mouseevent):
        """Test whether the mouse event occurred in the table.

        Returns T/F, {}
        """
        if six.callable(self._contains):
            return self._contains(self, mouseevent)

        # TODO: Return index of the cell containing the cursor so that the user
        # doesn't have to bind to each one individually.
        if self._cachedRenderer is not None:
            boxes = [self._cells[pos].get_window_extent(self._cachedRenderer)
                     for pos in six.iterkeys(self._cells)
                     if pos[0] >= 0 and pos[1] >= 0]
            bbox = Bbox.union(boxes)
            return bbox.contains(mouseevent.x, mouseevent.y), {}
        else:
            return False, {}

    def draw_markers(self, gc, marker_path, marker_trans, path, trans, rgbFace=None):
        if not len(path.vertices):
            return

        writer = self.writer
        path_data = self._convert_path(
            marker_path,
            marker_trans + Affine2D().scale(1.0, -1.0),
            simplify=False)
        style = self._get_style_dict(gc, rgbFace)
        dictkey = (path_data, generate_css(style))
        oid = self._markers.get(dictkey)
        for key in list(six.iterkeys(style)):
            if not key.startswith('stroke'):
                del style[key]
        style = generate_css(style)

        if oid is None:
            oid = self._make_id('m', dictkey)
            writer.start('defs')
            writer.element('path', id=oid, d=path_data, style=style)
            writer.end('defs')
            self._markers[dictkey] = oid

        attrib = {}
        clipid = self._get_clip(gc)
        if clipid is not None:
            attrib['clip-path'] = 'url(#%s)' % clipid
        writer.start('g', attrib=attrib)

        trans_and_flip = self._make_flip_transform(trans)
        attrib = {'xlink:href': '#%s' % oid}
        clip = (0, 0, self.width*72, self.height*72)
        for vertices, code in path.iter_segments(
                trans_and_flip, clip=clip, simplify=False):
            if len(vertices):
                x, y = vertices[-2:]
                attrib['x'] = short_float_fmt(x)
                attrib['y'] = short_float_fmt(y)
                attrib['style'] = self._get_style(gc, rgbFace)
                writer.element('use', attrib=attrib)
        writer.end('g')

    def pprint_getters(self):
        """
        Return the getters and actual values as list of strings.
        """

        d = self.properties()
        names = list(six.iterkeys(d))
        names.sort()
        lines = []
        for name in names:
            val = d[name]
            if getattr(val, "shape", ()) != () and len(val) > 6:
                s = str(val[:6]) + "..."
            else:
                s = str(val)
            s = s.replace("\n", " ")
            if len(s) > 50:
                s = s[:50] + "..."
            name = self.aliased_name(name)
            lines.append("    %s = %s" % (name, s))
        return lines

def findSystemFonts(fontpaths=None, fontext='ttf'):
    """
    Search for fonts in the specified font paths.  If no paths are
    given, will use a standard set of system paths, as well as the
    list of fonts tracked by fontconfig if fontconfig is installed and
    available.  A list of TrueType fonts are returned by default with
    AFM fonts as an option.
    """
    fontfiles = {}
    fontexts = get_fontext_synonyms(fontext)

    if fontpaths is None:
        if sys.platform == 'win32':
            fontdir = win32FontDirectory()

            fontpaths = [fontdir]
            # now get all installed fonts directly...
            for f in win32InstalledFonts(fontdir):
                base, ext = os.path.splitext(f)
                if len(ext)>1 and ext[1:].lower() in fontexts:
                    fontfiles[f] = 1
        else:
            fontpaths = X11FontDirectories
            # check for OS X & load its fonts if present
            if sys.platform == 'darwin':
                for f in OSXInstalledFonts(fontext=fontext):
                    fontfiles[f] = 1

            for f in get_fontconfig_fonts(fontext):
                fontfiles[f] = 1

    elif isinstance(fontpaths, six.string_types):
        fontpaths = [fontpaths]

    for path in fontpaths:
        files = list_fonts(path, fontexts)
        for fname in files:
            fontfiles[os.path.abspath(fname)] = 1

    return [fname for fname in six.iterkeys(fontfiles) if os.path.exists(fname)]