Use isinstance in is_string_like (#2660)

See https://github.com/matplotlib/matplotlib/pull/8011

6 files changed, 21 insertions, 25 deletions

diff --git a/networkx/algorithms/operators/all.py b/networkx/algorithms/operators/all.py
index f37cb40c..21339a35 100644
--- a/networkx/algorithms/operators/all.py
+++ b/networkx/algorithms/operators/all.py
@@ -11,7 +11,6 @@ try:
 except ImportError:  # Python3 has zip_longest
     from itertools import zip_longest
 import networkx as nx
-# from networkx.utils import is_string_like
 
 __author__ = """\n""".join(['Robert King <kingrobertking@gmail.com>',
                             'Aric Hagberg <aric.hagberg@gmail.com>'])
diff --git a/networkx/drawing/nx_pylab.py b/networkx/drawing/nx_pylab.py
index 5832b9a7..1927d0c7 100644
--- a/networkx/drawing/nx_pylab.py
+++ b/networkx/drawing/nx_pylab.py
@@ -22,6 +22,7 @@ pygraphviz:     http://pygraphviz.github.io/
 
 """
 import networkx as nx
+from networkx.utils import is_string_like
 from networkx.drawing.layout import shell_layout, \
     circular_layout, kamada_kawai_layout, spectral_layout, \
     spring_layout, random_layout
@@ -39,13 +40,6 @@ __all__ = ['draw',
            'draw_spring',
            'draw_shell']
 
-# 2.x/3.x compatibility
-try:
-    basestring
-except NameError:
-    basestring = str
-    unicode = str
-
 
 def draw(G, pos=None, ax=None, **kwds):
     """Draw the graph G with Matplotlib.
@@ -526,15 +520,15 @@ def draw_networkx_edges(G, pos,
     else:
         lw = width
 
-    if not isinstance(edge_color, basestring) \
+    if not is_string_like(edge_color) \
             and cb.iterable(edge_color) \
             and len(edge_color) == len(edge_pos):
-        if np.alltrue([isinstance(c, basestring) for c in edge_color]):
+        if np.alltrue([is_string_like(c) for c in edge_color]):
             # (should check ALL elements)
             # list of color letters such as ['k','r','k',...]
             edge_colors = tuple([colorConverter.to_rgba(c, alpha)
                                  for c in edge_color])
-        elif np.alltrue([not isinstance(c, basestring) for c in edge_color]):
+        elif np.alltrue([not is_string_like(c) for c in edge_color]):
             # If color specs are given as (rgb) or (rgba) tuples, we're OK
             if np.alltrue([cb.iterable(c) and len(c) in (3, 4)
                           for c in edge_color]):
@@ -545,7 +539,7 @@ def draw_networkx_edges(G, pos,
         else:
             raise ValueError('edge_color must consist of either color names or numbers')
     else:
-        if isinstance(edge_color, basestring) or len(edge_color) == 1:
+        if is_string_like(edge_color) or len(edge_color) == 1:
             edge_colors = (colorConverter.to_rgba(edge_color, alpha), )
         else:
             raise ValueError(
@@ -726,7 +720,7 @@ def draw_networkx_labels(G, pos,
     text_items = {}  # there is no text collection so we'll fake one
     for n, label in labels.items():
         (x, y) = pos[n]
-        if not isinstance(label, basestring):
+        if not is_string_like(label):
             label = str(label)  # this will cause "1" and 1 to be labeled the same
         t = ax.text(x, y,
                     label,
@@ -864,7 +858,7 @@ def draw_networkx_edge_labels(G, pos,
                         ec=(1.0, 1.0, 1.0),
                         fc=(1.0, 1.0, 1.0),
                         )
-        if not isinstance(label, basestring):
+        if not is_string_like(label):
             label = str(label)  # this will cause "1" and 1 to be labeled the same
 
         # set optional alignment
diff --git a/networkx/readwrite/leda.py b/networkx/readwrite/leda.py
index b96a590f..3ee4fc45 100644
--- a/networkx/readwrite/leda.py
+++ b/networkx/readwrite/leda.py
@@ -32,7 +32,7 @@ def read_leda(path, encoding='UTF-8'):
     Parameters
     ----------
     path : file or string
-       File or filename to read.  Filenames ending in .gz or .bz2  will be 
+       File or filename to read.  Filenames ending in .gz or .bz2  will be
        uncompressed.
 
     Returns
diff --git a/networkx/readwrite/p2g.py b/networkx/readwrite/p2g.py
index 910a6dd5..934c4564 100644
--- a/networkx/readwrite/p2g.py
+++ b/networkx/readwrite/p2g.py
@@ -1,5 +1,5 @@
 """
-This module provides the following: read and write of p2g format 
+This module provides the following: read and write of p2g format
 used in metabolic pathway studies.
 
 See https://web.archive.org/web/20080626113807/http://www.cs.purdue.edu/homes/koyuturk/pathway/ for a description.
@@ -66,7 +66,7 @@ def write_p2g(G, path, encoding='utf-8'):
 
 @open_file(0, mode='r')
 def read_p2g(path, encoding='utf-8'):
-    """Read graph in p2g format from path. 
+    """Read graph in p2g format from path.
 
     Returns
     -------
@@ -83,7 +83,7 @@ def read_p2g(path, encoding='utf-8'):
 
 
 def parse_p2g(lines):
-    """Parse p2g format graph from string or iterable. 
+    """Parse p2g format graph from string or iterable.
 
     Returns
     -------
diff --git a/networkx/readwrite/pajek.py b/networkx/readwrite/pajek.py
index f75aaa8b..1409d89d 100644
--- a/networkx/readwrite/pajek.py
+++ b/networkx/readwrite/pajek.py
@@ -205,10 +205,10 @@ def parse_pajek(lines):
                 G.nodes[label].update(extra_attr)
         elif l.lower().startswith("*edges") or l.lower().startswith("*arcs"):
             if l.lower().startswith("*edge"):
-               # switch from multidigraph to multigraph
+                # switch from multidigraph to multigraph
                 G = nx.MultiGraph(G)
             if l.lower().startswith("*arcs"):
-               # switch to directed with multiple arcs for each existing edge
+                # switch to directed with multiple arcs for each existing edge
                 G = G.to_directed()
             for l in lines:
                 try:
diff --git a/networkx/utils/misc.py b/networkx/utils/misc.py
index ba5ca78c..4e826d6d 100644
--- a/networkx/utils/misc.py
+++ b/networkx/utils/misc.py
@@ -47,6 +47,13 @@ except ImportError:
             total = func(total, element)
             yield total
 
+# 2.x/3.x compatibility
+try:
+    basestring
+except NameError:
+    basestring = str
+    unicode = str
+
 # some cookbook stuff
 # used in deciding whether something is a bunch of nodes, edges, etc.
 # see G.add_nodes and others in Graph Class in networkx/base.py
@@ -54,11 +61,7 @@ except ImportError:
 
 def is_string_like(obj):  # from John Hunter, types-free version
     """Check if obj is string."""
-    try:
-        obj + ''
-    except (TypeError, ValueError):
-        return False
-    return True
+    return isinstance(obj, basestring)
 
 
 def iterable(obj):