Completely deprecate is_string_like.

I had missed that numpy's `str_` (and `unicode_` on Py2) derive from the corresponding builtin type(s), so `isinstance(x, six.string_types)` is just as good.
tacaswell · Apr 17, 2017 · Jan 31, 2017 · Jan 31, 2017 · Apr 15, 2017 · Apr 15, 2017
commit 5ca32abb4633431783c415c147ee943a32208bda
diff --git a/doc/api/api_changes/2017-01-30-AL_is_numlike_stringlike.rst b/doc/api/api_changes/2017-01-30-AL_is_numlike_stringlike.rst
@@ -1,8 +1,10 @@
-`cbook.is_numlike` and `cbook.is_string_like` only perform an instance check
-````````````````````````````````````````````````````````````````````````````
+`cbook.is_numlike` only performs an instance check, `cbook.is_string_like` is deprecated
+````````````````````````````````````````````````````````````````````````````````````````
 
-`cbook.is_numlike` and `cbook.is_string_like` now only check that
-their argument is an instance of ``(numbers.Number, np.Number)`` and
-``(six.string_types, np.str_, np.unicode_)`` respectively.  In particular, this
-means that arrays are now never num-like or string-like regardless of their
-dtype.
+`cbook.is_numlike` now only checks that its argument is an instance of
+``(numbers.Number, np.Number)`` and.  In particular, this means that arrays are
+now not num-like.
+
+`cbook.is_string_like` and `cbook.is_sequence_of_strings` have been
+deprecated.  Use ``isinstance(obj, six.string_types)`` and ``all(isinstance(o,
+six.string_types) for o in obj) and not iterable(obj)`` instead.
diff --git a/examples/misc/rc_traits.py b/examples/misc/rc_traits.py
@@ -10,7 +10,6 @@
 import os
 import re
 import traits.api as traits
-from matplotlib.cbook import is_string_like
 from matplotlib.artist import Artist
 
 doprint = True
@@ -75,7 +74,7 @@ def tuple_to_rgba(ob, name, val):
 def hex_to_rgba(ob, name, val):
     rgx = re.compile('^#[0-9A-Fa-f]{6}$')
 
-    if not is_string_like(val):
+    if not isinstance(val, six.string_types):
         raise TypeError
     if rgx.match(val) is None:
         raise ValueError

diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -121,7 +121,7 @@
 # cbook must import matplotlib only within function
 # definitions, so it is safe to import from it here.
 from . import cbook
-from matplotlib.cbook import (is_string_like,
+from matplotlib.cbook import (
                               mplDeprecation,
                               dedent, get_label,
                               sanitize_sequence)
@@ -1225,7 +1225,7 @@ def rc(group, **kwargs):
         'aa':  'antialiased',
         }
 
-    if is_string_like(group):
+    if isinstance(group, six.string_types):
         group = (group,)
     for g in group:
         for k, v in six.iteritems(kwargs):

diff --git a/lib/matplotlib/animation.py b/lib/matplotlib/animation.py
@@ -38,7 +38,7 @@
 import contextlib
 import tempfile
 import warnings
-from matplotlib.cbook import iterable, is_string_like, deprecated
+from matplotlib.cbook import iterable, deprecated
 from matplotlib.compat import subprocess
 from matplotlib import verbose
 from matplotlib import rcParams, rcParamsDefault, rc_context
@@ -1023,7 +1023,7 @@ class to use, such as 'ffmpeg' or 'mencoder'. If `None`,
         # to use
         if writer is None:
             writer = rcParams['animation.writer']
-        elif (not is_string_like(writer) and
+        elif (not isinstance(writer, six.string_types) and
                 any(arg is not None
                     for arg in (fps, codec, bitrate, extra_args, metadata))):
             raise RuntimeError('Passing in values for arguments '
@@ -1068,7 +1068,7 @@ class to use, such as 'ffmpeg' or 'mencoder'. If `None`,
 
         # If we have the name of a writer, instantiate an instance of the
         # registered class.
-        if is_string_like(writer):
+        if isinstance(writer, six.string_types):
             if writer in writers.avail:
                 writer = writers[writer](fps, codec, bitrate,
                                          extra_args=extra_args,

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -17,7 +17,7 @@
 
 import matplotlib.cbook as cbook
 from matplotlib.cbook import (mplDeprecation, STEP_LOOKUP_MAP,
-                              iterable, is_string_like,
+                              iterable,
                               safe_first_element)
 import matplotlib.collections as mcoll
 import matplotlib.colors as mcolors
@@ -2662,7 +2662,7 @@ def get_next_color():
             if autopct is not None:
                 xt = x + pctdistance * radius * math.cos(thetam)
                 yt = y + pctdistance * radius * math.sin(thetam)
-                if is_string_like(autopct):
+                if isinstance(autopct, six.string_types):
                     s = autopct % (100. * frac)
                 elif callable(autopct):
                     s = autopct(100. * frac)
@@ -5472,8 +5472,8 @@ def pcolor(self, *args, **kwargs):
         # makes artifacts that are often disturbing.
         if 'antialiased' in kwargs:
             kwargs['antialiaseds'] = kwargs.pop('antialiased')
-        if 'antialiaseds' not in kwargs and (is_string_like(ec) and
-                                             ec.lower() == "none"):
+        if 'antialiaseds' not in kwargs and (
+                isinstance(ec, six.string_types) and ec.lower() == "none"):
             kwargs['antialiaseds'] = False
 
         kwargs.setdefault('snap', False)
@@ -6380,7 +6380,7 @@ def hist(self, x, bins=None, range=None, normed=False, weights=None,
 
         if label is None:
             labels = [None]
-        elif is_string_like(label):
+        elif isinstance(label, six.string_types):
             labels = [label]
         else:
             labels = [six.text_type(lab) for lab in label]

diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -352,7 +352,7 @@ def _makefill(self, x, y, kw, kwargs):
 
     def _plot_args(self, tup, kwargs):
         ret = []
-        if len(tup) > 1 and is_string_like(tup[-1]):
+        if len(tup) > 1 and isinstance(tup[-1], six.string_types):
             linestyle, marker, color = _process_plot_format(tup[-1])
             tup = tup[:-1]
         elif len(tup) == 3:
@@ -398,7 +398,7 @@ def _plot_args(self, tup, kwargs):
     def _grab_next_args(self, *args, **kwargs):
         while args:
             this, args = args[:2], args[2:]
-            if args and is_string_like(args[0]):
+            if args and isinstance(args[0], six.string_types):
                 this += args[0],
                 args = args[1:]
             for seg in self._plot_args(this, kwargs):
@@ -1281,7 +1281,7 @@ def set_aspect(self, aspect, adjustable=None, anchor=None):
           etc.
           =====   =====================
         """
-        if cbook.is_string_like(aspect) and aspect in ('equal', 'auto'):
+        if isinstance(aspect, six.string_types) and aspect in ('equal', 'auto'):
             self._aspect = aspect
         else:
             self._aspect = float(aspect)  # raise ValueError if necessary
@@ -1556,7 +1556,7 @@ def axis(self, *v, **kwargs):
 
         emit = kwargs.get('emit', True)
 
-        if len(v) == 1 and is_string_like(v[0]):
+        if len(v) == 1 and isinstance(v[0], six.string_types):
             s = v[0].lower()
             if s == 'on':
                 self.set_axis_on()

diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -129,7 +129,7 @@ def get_registered_canvas_class(format):
     if format not in _default_backends:
         return None
     backend_class = _default_backends[format]
-    if cbook.is_string_like(backend_class):
+    if isinstance(backend_class, six.string_types):
         backend_class = importlib.import_module(backend_class).FigureCanvas
         _default_backends[format] = backend_class
     return backend_class
@@ -2090,11 +2090,11 @@ def print_figure(self, filename, dpi=None, facecolor=None, edgecolor=None,
 
         if format is None:
             # get format from filename, or from backend's default filetype
-            if cbook.is_string_like(filename):
+            if isinstance(filename, six.string_types):
                 format = os.path.splitext(filename)[1][1:]
             if format is None or format == '':
                 format = self.get_default_filetype()
-                if cbook.is_string_like(filename):
+                if isinstance(filename, six.string_types):
                     filename = filename.rstrip('.') + '.' + format
         format = format.lower()
 

diff --git a/lib/matplotlib/backends/backend_agg.py b/lib/matplotlib/backends/backend_agg.py
@@ -31,7 +31,7 @@
 from matplotlib import verbose, rcParams, __version__
 from matplotlib.backend_bases import (RendererBase, FigureManagerBase,
                                       FigureCanvasBase)
-from matplotlib.cbook import is_string_like, maxdict, restrict_dict
+from matplotlib.cbook import maxdict, restrict_dict
 from matplotlib.figure import Figure
 from matplotlib.font_manager import findfont, get_font
 from matplotlib.ft2font import (LOAD_FORCE_AUTOHINT, LOAD_NO_HINTING,
@@ -530,7 +530,7 @@ def print_raw(self, filename_or_obj, *args, **kwargs):
         renderer = self.get_renderer()
         original_dpi = renderer.dpi
         renderer.dpi = self.figure.dpi
-        if is_string_like(filename_or_obj):
+        if isinstance(filename_or_obj, six.string_types):
             fileobj = open(filename_or_obj, 'wb')
             close = True
         else:
@@ -549,7 +549,7 @@ def print_png(self, filename_or_obj, *args, **kwargs):
         renderer = self.get_renderer()
         original_dpi = renderer.dpi
         renderer.dpi = self.figure.dpi
-        if is_string_like(filename_or_obj):
+        if isinstance(filename_or_obj, six.string_types):
             filename_or_obj = open(filename_or_obj, 'wb')
             close = True
         else:

diff --git a/lib/matplotlib/backends/backend_cairo.py b/lib/matplotlib/backends/backend_cairo.py
@@ -51,7 +51,6 @@ def _fn_name(): return sys._getframe(1).f_code.co_name
 
 from matplotlib.backend_bases import RendererBase, GraphicsContextBase,\
      FigureManagerBase, FigureCanvasBase
-from matplotlib.cbook        import is_string_like
 from matplotlib.figure       import Figure
 from matplotlib.mathtext     import MathTextParser
 from matplotlib.path         import Path
@@ -555,7 +554,7 @@ def _save (self, fo, format, **kwargs):
                 raise RuntimeError ('cairo has not been compiled with SVG '
                                     'support enabled')
             if format == 'svgz':
-                if is_string_like(fo):
+                if isinstance(fo, six.string_types):
                     fo = gzip.GzipFile(fo, 'wb')
                 else:
                     fo = gzip.GzipFile(None, 'wb', fileobj=fo)

diff --git a/lib/matplotlib/backends/backend_gdk.py b/lib/matplotlib/backends/backend_gdk.py
@@ -26,7 +26,7 @@ def fn_name(): return sys._getframe(1).f_code.co_name
 from matplotlib._pylab_helpers import Gcf
 from matplotlib.backend_bases import RendererBase, GraphicsContextBase, \
      FigureManagerBase, FigureCanvasBase
-from matplotlib.cbook import is_string_like, restrict_dict, warn_deprecated
+from matplotlib.cbook import restrict_dict, warn_deprecated
 from matplotlib.figure import Figure
 from matplotlib.mathtext import MathTextParser
 from matplotlib.transforms import Affine2D

diff --git a/lib/matplotlib/backends/backend_gtk.py b/lib/matplotlib/backends/backend_gtk.py
@@ -34,7 +34,7 @@ def fn_name(): return sys._getframe(1).f_code.co_name
 from matplotlib.backend_bases import ShowBase
 
 from matplotlib.backends.backend_gdk import RendererGDK, FigureCanvasGDK
-from matplotlib.cbook import is_string_like, is_writable_file_like
+from matplotlib.cbook import is_writable_file_like
 from matplotlib.figure import Figure
 from matplotlib.widgets import SubplotTool
 from matplotlib.cbook import warn_deprecated
@@ -490,7 +490,7 @@ def _print_image(self, filename, format, *args, **kwargs):
 
             options['quality'] = str(options['quality'])
 
-        if is_string_like(filename):
+        if isinstance(filename, six.string_types):
             try:
                 pixbuf.save(filename, format, options=options)
             except gobject.GError as exc:
@@ -908,7 +908,7 @@ class DialogLineprops(object):
     linestyled = {s: i for i, s in enumerate(linestyles)}
 
     markers =  [m for m in markers.MarkerStyle.markers
-                if cbook.is_string_like(m)]
+                if isinstance(m, six.string_types)]
     markerd = {s: i for i, s in enumerate(markers)}
 
     def __init__(self, lines):
@@ -1068,7 +1068,7 @@ def error_msg_gtk(msg, parent=None):
         if parent.flags() & gtk.TOPLEVEL == 0:
             parent = None
 
-    if not is_string_like(msg):
+    if not isinstance(msg, six.string_types):
         msg = ','.join(map(str,msg))
 
     dialog = gtk.MessageDialog(

diff --git a/lib/matplotlib/backends/backend_gtk3.py b/lib/matplotlib/backends/backend_gtk3.py
@@ -35,7 +35,7 @@ def fn_name(): return sys._getframe(1).f_code.co_name
 from matplotlib.backend_managers import ToolManager
 from matplotlib import backend_tools
 
-from matplotlib.cbook import is_string_like, is_writable_file_like
+from matplotlib.cbook import is_writable_file_like
 from matplotlib.figure import Figure
 from matplotlib.widgets import SubplotTool
 
@@ -954,7 +954,7 @@ def error_msg_gtk(msg, parent=None):
         if not parent.is_toplevel():
             parent = None
 
-    if not is_string_like(msg):
+    if not isinstance(msg, six.string_types):
         msg = ','.join(map(str,msg))
 
     dialog = Gtk.MessageDialog(

diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
@@ -34,7 +34,7 @@
 from matplotlib.backend_bases import (RendererBase, GraphicsContextBase,
                                       FigureManagerBase, FigureCanvasBase)
 from matplotlib.backends.backend_mixed import MixedModeRenderer
-from matplotlib.cbook import (Bunch, is_string_like, get_realpath_and_stat,
+from matplotlib.cbook import (Bunch, get_realpath_and_stat,
                               is_writable_file_like, maxdict)
 from matplotlib.figure import Figure
 from matplotlib.font_manager import findfont, is_opentype_cff_font, get_font
@@ -434,7 +434,7 @@ def __init__(self, filename, metadata=None):
         self.passed_in_file_object = False
         self.original_file_like = None
         self.tell_base = 0
-        if is_string_like(filename):
+        if isinstance(filename, six.string_types):
             fh = open(filename, 'wb')
         elif is_writable_file_like(filename):
             try:
@@ -1564,6 +1564,9 @@ def writeXref(self):
     def writeInfoDict(self):
         """Write out the info dictionary, checking it for good form"""
 
+        def is_string_like(x):
+            return isinstance(x, six.string_types)
+
         def is_date(x):
             return isinstance(x, datetime)
 

diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
@@ -25,7 +25,7 @@
 from matplotlib.text import Text
 from matplotlib.path import Path
 from matplotlib import _png, rcParams
-from matplotlib.cbook import is_string_like, is_writable_file_like
+from matplotlib.cbook import is_writable_file_like
 from matplotlib.compat import subprocess
 from matplotlib.compat.subprocess import check_output
 
@@ -859,7 +859,7 @@ def print_pgf(self, fname_or_fh, *args, **kwargs):
             return
 
         # figure out where the pgf is to be written to
-        if is_string_like(fname_or_fh):
+        if isinstance(fname_or_fh, six.string_types):
             with codecs.open(fname_or_fh, "w", encoding="utf-8") as fh:
                 self._print_pgf_to_fh(fh, *args, **kwargs)
         elif is_writable_file_like(fname_or_fh):
@@ -923,7 +923,7 @@ def print_pdf(self, fname_or_fh, *args, **kwargs):
             return
 
         # figure out where the pdf is to be written to
-        if is_string_like(fname_or_fh):
+        if isinstance(fname_or_fh, six.string_types):
             with open(fname_or_fh, "wb") as fh:
                 self._print_pdf_to_fh(fh, *args, **kwargs)
         elif is_writable_file_like(fname_or_fh):
@@ -959,7 +959,7 @@ def print_png(self, fname_or_fh, *args, **kwargs):
             self._print_pgf_to_fh(None, *args, **kwargs)
             return
 
-        if is_string_like(fname_or_fh):
+        if isinstance(fname_or_fh, six.string_types):
             with open(fname_or_fh, "wb") as fh:
                 self._print_png_to_fh(fh, *args, **kwargs)
         elif is_writable_file_like(fname_or_fh):

diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
@@ -18,7 +18,7 @@ def _fn_name(): return sys._getframe(1).f_code.co_name
 from matplotlib.backend_bases import RendererBase, GraphicsContextBase,\
      FigureManagerBase, FigureCanvasBase
 
-from matplotlib.cbook import is_string_like, get_realpath_and_stat, \
+from matplotlib.cbook import get_realpath_and_stat, \
     is_writable_file_like, maxdict, file_requires_unicode
 from matplotlib.compat.subprocess import subprocess
 from matplotlib.figure import Figure
@@ -141,7 +141,7 @@ def _get_papertype(w, h):
         return 'a0'
 
 def _num_to_str(val):
-    if is_string_like(val): return val
+    if isinstance(val, six.string_types): return val
 
     ival = int(val)
     if val==ival: return str(ival)
@@ -977,7 +977,7 @@ def _print_figure(self, outfile, format, dpi=72, facecolor='w', edgecolor='w',
         """
         isEPSF = format == 'eps'
         passed_in_file_object = False
-        if is_string_like(outfile):
+        if isinstance(outfile, six.string_types):
             title = outfile
         elif is_writable_file_like(outfile):
             title = None
@@ -1220,7 +1220,7 @@ def _print_figure_tex(self, outfile, format, dpi, facecolor, edgecolor,
         the key 'Creator' is used.
         """
         isEPSF = format == 'eps'
-        if is_string_like(outfile):
+        if isinstance(outfile, six.string_types):
             title = outfile
         elif is_writable_file_like(outfile):
             title = None

diff --git a/lib/matplotlib/backends/backend_qt4.py b/lib/matplotlib/backends/backend_qt4.py
@@ -10,7 +10,6 @@
 
 import matplotlib
 
-from matplotlib.cbook import is_string_like
 from matplotlib.backend_bases import FigureManagerBase
 from matplotlib.backend_bases import FigureCanvasBase
 from matplotlib.backend_bases import NavigationToolbar2