ENH: Modify Directory and File traits to get along with pathlib

Closes #2959

Author: oesteban

nipype/interfaces/base/traits_extension.py

@@ -38,6 +38,12 @@
 if USING_PATHLIB2:
     from future.types.newstr import newstr
 
+try:
+    from pathlib import Path
+except ImportError:
+    from pathlib2 import Path
+
+
 if traits_version < '3.7.0':
     raise ImportError('Traits version 3.7.0 or higher must be installed')
 
@@ -153,7 +159,6 @@ def validate(self, objekt, name, value, return_pathlike=False):
 
         return value
 
-
 class Directory(BasePath):
     """
     Defines a trait whose value must be a directory path.
@@ -194,14 +199,12 @@ class Directory(BasePath):
     >>> a.foo
     'relative_dir'
 
-
     >>> class A(TraitedSpec):
     ...     foo = Directory('tmpdir')
     >>> a = A()
     >>> a.foo  # doctest: +ELLIPSIS
     <undefined>
 
-
     >>> class A(TraitedSpec):
     ...     foo = Directory('tmpdir', usedefault=True)
     >>> a = A()

nipype/interfaces/spm/base.py

@@ -605,3 +605,4 @@ def __init__(self, value=NoDefaultSpecified, exists=False, resolve=False, **meta
         super(ImageFileSPM, self).__init__(
             value=value, exists=exists, types=['nifti1', 'nifti2'],
             allow_compressed=False, resolve=resolve, **metadata)
+