Use safe version of os.path.isfile

panel/io/save.py

@@ -83,10 +83,9 @@ def save(panel, filename, title=None, resources=None, template=None,
     """
     from ..pane import PaneBase
 
-    if isinstance(panel, PaneBase):
-        if len(panel.layout) >= 1:
-            panel = panel.layout
-
+    if isinstance(panel, PaneBase) and len(panel.layout) > 1:
+        panel = panel.layout
+
     doc = Document()
     comm = Comm()
     with config.set(embed=embed):

panel/pane/base.py

@@ -273,7 +273,10 @@ def get_pane_type(cls, obj, **kwargs):
         for p in param.concrete_descendents(PaneBase).values():
             if p.priority is None:
                 applies = True
-                priority = p.applies(obj, **(kwargs if p._applies_kw else {}))
+                try:
+                    priority = p.applies(obj, **(kwargs if p._applies_kw else {}))
+                except:
+                    priority = False
             else:
                 applies = None
                 priority = p.priority
@@ -289,7 +292,10 @@ def get_pane_type(cls, obj, **kwargs):
         pane_types = reversed(sorted(descendents, key=lambda x: x[0]))
         for _, applies, pane_type in pane_types:
             if applies is None:
-                applies = pane_type.applies(obj, **(kwargs if pane_type._applies_kw else {}))
+                try:
+                    applies = pane_type.applies(obj, **(kwargs if pane_type._applies_kw else {}))
+                except:
+                    applies = False
             if not applies:
                 continue
             return pane_type

panel/pane/image.py

@@ -5,14 +5,14 @@
 from __future__ import absolute_import, division, unicode_literals
 
 import base64
-import os
 
 from io import BytesIO
 from six import string_types
 
 import param
 
 from .markup import escape, DivPaneBase
+from ..util import isfile, isurl
 
 
 class ImageBase(DivPaneBase):
@@ -42,24 +42,14 @@ def applies(cls, obj):
         if hasattr(obj, '_repr_{}_'.format(imgtype)):
             return True
         if isinstance(obj, string_types):
-            if os.path.isfile(obj) and obj.endswith('.'+imgtype):
+            if isfile(obj) and obj.endswith('.'+imgtype):
                 return True
-            if cls._is_url(obj):
+            if isurl(obj, [cls.imgtype]):
                 return True
         if hasattr(obj, 'read'):  # Check for file like object
             return True
         return False
 
-    @classmethod
-    def _is_url(cls, obj):
-        if isinstance(obj, string_types):
-            lower_string = obj.lower()
-            return (
-                lower_string.startswith('http://')
-                or lower_string.startswith('https://')
-            ) and lower_string.endswith('.'+cls.imgtype)
-        return False
-
     def _type_error(self, object):
         if isinstance(object, string_types):
             raise ValueError("%s pane cannot parse string that is not a filename "
@@ -70,12 +60,12 @@ def _img(self):
         if hasattr(self.object, '_repr_{}_'.format(self.imgtype)):
             return getattr(self.object, '_repr_' + self.imgtype + '_')()
         if isinstance(self.object, string_types):
-            if os.path.isfile(self.object):
+            if isfile(self.object):
                 with open(self.object, 'rb') as f:
                     return f.read()
         if hasattr(self.object, 'read'):
             return self.object.read()
-        if self._is_url(self.object):
+        if isurl(self.object, [self.imgtype]):
             import requests
             r = requests.request(url=self.object, method='GET')
             return r.content

panel/pane/media.py

@@ -13,6 +13,7 @@
 import param
 
 from ..models import Audio as _BkAudio, Video as _BkVideo
+from ..util import isfile, isurl
 from .base import PaneBase
 
 
@@ -51,24 +52,14 @@ class _MediaBase(PaneBase):
     @classmethod
     def applies(cls, obj):
         if isinstance(obj, string_types):
-            if os.path.isfile(obj) and any(obj.endswith('.'+fmt) for fmt in cls._formats):
+            if isfile(obj) and any(obj.endswith('.'+fmt) for fmt in cls._formats):
                 return True
-            if cls._is_url(obj):
+            if isurl(obj, cls._formats):
                 return True
         if hasattr(obj, 'read'):  # Check for file like object
             return True
         return False
 
-    @classmethod
-    def _is_url(cls, obj):
-        if isinstance(obj, string_types):
-            lower_string = obj.lower()
-            return (
-                lower_string.startswith('http://')
-                or lower_string.startswith('https://')
-            ) and any(lower_string.endswith('.'+fmt) for fmt in cls._formats)
-        return False
-
     def _init_properties(self):
         return {k: v for k, v in self.param.get_param_values()
                 if v is not None and k not in ['default_layout']}

panel/pane/vtk/vtk.py

@@ -5,7 +5,6 @@
 from __future__ import absolute_import, division, unicode_literals
 
 import sys
-import os
 import base64
 
 try:
@@ -21,6 +20,7 @@
 from pyviz_comms import JupyterComm
 
 from ..base import PaneBase
+from ...util import isfile
 
 if sys.version_info >= (2, 7):
     base64encode = lambda x: base64.b64encode(x).decode('utf-8')
@@ -292,7 +292,7 @@ def register_serializer(cls, class_type, serializer):
     def _get_vtkjs(self):
         if self._vtkjs is None and self.object is not None:
             if isinstance(self.object, string_types) and self.object.endswith('.vtkjs'):
-                if os.path.isfile(self.object):
+                if isfile(self.object):
                     with open(self.object, 'rb') as f:
                         vtkjs = f.read()
                 else:

panel/util.py

@@ -3,12 +3,12 @@
 """
 from __future__ import absolute_import, division, unicode_literals
 
-import re
-import sys
+import datetime as dt
 import inspect
 import numbers
-import datetime as dt
-
+import os
+import re
+import sys
 
 from collections import defaultdict, OrderedDict
 from datetime import datetime
@@ -33,6 +33,24 @@
     unicode = str
 
 
+def isfile(path):
+    """Safe version of os.path.isfile robust to path length issues on Windows"""
+    try:
+        return os.path.isfile(path)
+    except ValueError: # path too long for Windows
+        return False
+
+
+def isurl(obj, formats):
+    if not isinstance(obj, string_types):
+        return False
+    lower_string = obj.lower()
+    return (
+        lower_string.startswith('http://')
+        or lower_string.startswith('https://')
+    ) and any(lower_string.endswith('.'+fmt) for fmt in formats)
+
+
 def hashable(x):
     if isinstance(x, MutableSequence):
         return tuple(x)