Allow passing pathlib Paths without keyword arg

Don't need to use `filename=` now. Hacky but easier than the alternative of
`os.PathLike` (which doesn't exist in 3.5).

IPython/core/display.py

@@ -14,6 +14,7 b' import sys'
 import warnings
 from copy import deepcopy
 from os.path import splitext
+from pathlib import Path, PurePath
 
 from IPython.utils.py3compat import cast_unicode
 from IPython.testing.skipdoctest import skip_doctest
@@ -594,6 +595,9 b' class DisplayObject(object):'
         metadata : dict
             Dict of metadata associated to be the object when displayed
         """
+        if isinstance(data, (Path, PurePath)):
+            data = str(data)
+
         if data is not None and isinstance(data, str):
             if data.startswith('http') and url is None:
                 url = data
@@ -864,6 +868,9 b' class JSON(DisplayObject):'
 
     @data.setter
     def data(self, data):
+        if isinstance(data, (Path, PurePath)):
+            data = str(data)
+
         if isinstance(data, str):
             if getattr(self, 'filename', None) is None:
                 warnings.warn("JSON expects JSONable dict or list, not JSON strings")
@@ -1134,6 +1141,9 b' class Image(DisplayObject):'
         Image(url='http://www.google.fr/images/srpr/logo3w.png')
 
         """
+        if isinstance(data, (Path, PurePath)):
+            data = str(data)
+
         if filename is not None:
             ext = self._find_ext(filename)
         elif url is not None:
@@ -1338,6 +1348,9 b' class Video(DisplayObject):'
         Video('path/to/video.mp4', embed=True)
         Video(b'raw-videodata', embed=True)
         """
+        if isinstance(data, (Path, PurePath)):
+            data = str(data)
+
         if url is None and isinstance(data, str) and data.startswith(('http:', 'https:')):
             url = data
             data = None