ENH: Add LibraryBaseInterface

Author: effigies

nipype/interfaces/base/__init__.py

@@ -10,7 +10,7 @@
 """
 from .core import (Interface, BaseInterface, SimpleInterface, CommandLine,
                    StdOutCommandLine, MpiCommandLine, SEMLikeCommandLine,
-                   PackageInfo)
+                   LibraryBaseInterface, PackageInfo)
 
 from .specs import (BaseTraitedSpec, TraitedSpec, DynamicTraitedSpec,
                     BaseInterfaceInputSpec, CommandLineInputSpec,

nipype/interfaces/base/core.py

@@ -1267,6 +1267,35 @@ def _format_arg(self, name, spec, value):
         return super(SEMLikeCommandLine, self)._format_arg(name, spec, value)
 
 
+class LibraryBaseInterface(BaseInterface):
+    _pkg = None
+    imports = ()
+
+    def __init__(self, check_import=True, *args, **kwargs):
+        super(LibraryBaseInterface, self).__init__(*args, **kwargs)
+        if check_import:
+            import importlib
+            failed_imports = []
+            for pkg in (self._pkg,) + tuple(self.imports):
+                try:
+                    importlib.import_module(pkg)
+                except ImportError:
+                    failed_imports.append(pkg)
+            if failed_imports:
+                iflogger.warn('Unable to import %s; %s interface may fail to '
+                              'run', failed_imports, self.__class__.__name__)
+
+    @property
+    def version(self):
+        if self._version is None:
+            import importlib
+            try:
+                self._version = importlib.import_module(self._pkg).__version__
+            except (ImportError, AttributeError):
+                pass
+        return super(LibraryBaseInterface, self).version
+
+
 class PackageInfo(object):
     _version = None
     version_cmd = None

nipype/interfaces/dipy/base.py

@@ -6,7 +6,7 @@
 import os.path as op
 import numpy as np
 from ... import logging
-from ..base import (traits, File, isdefined, BaseInterface,
+from ..base import (traits, File, isdefined, LibraryBaseInterface,
                     BaseInterfaceInputSpec)
 
 IFLOGGER = logging.getLogger('interface')
@@ -32,16 +32,11 @@ def dipy_version():
     return dipy.__version__
 
 
-class DipyBaseInterface(BaseInterface):
+class DipyBaseInterface(LibraryBaseInterface):
     """
     A base interface for py:mod:`dipy` computations
     """
-
-    def __init__(self, **inputs):
-        if no_dipy():
-            IFLOGGER.warn('dipy was not found')
-            # raise ImportError('dipy was not found')
-        super(DipyBaseInterface, self).__init__(**inputs)
+    _pkg = 'dipy'
 
 
 class DipyBaseInterfaceInputSpec(BaseInterfaceInputSpec):