convert prefs dict to a class for futureproofing

docs/api.rst

@@ -64,13 +64,13 @@ methods in the current release of Neurolearn.
     :members:
 
 :mod:`nltools.utils`: Utilities
-==============================
+===============================
 
 .. automodule:: nltools.utils
     :members:
 
 :mod:`nltools.prefs`: Preferences
-================================
+=================================
 
 This module can be used to adjust the default MNI template settings that are used
 internally by all `Brain_Data` operations. By default all operations are performed in
@@ -93,8 +93,12 @@ Alternatively this module can be used to switch between 2mm or 3mm MNI spaces wi
     from nltools.prefs import MNI_Template, resolve_mni_path
     from nltools.data import Brain_Data
 
+    # Update the resolution globally
     MNI_Template['resolution'] = '3mm'
 
+    # This works too:
+    MNI_Template.resolution = 3
+
     # my_brain will be resampled to 3mm and future operation will be in 3mm space
     brain = Brain_Data('my_brain.nii.gz') 
 

nltools/prefs.py

@@ -3,13 +3,95 @@
 
 __all__ = ["MNI_Template", "resolve_mni_path"]
 
-MNI_Template = dict(
-    resolution="2mm",
-    mask_type="with_ventricles",
-    mask=os.path.join(get_resource_path(), "MNI152_T1_2mm_brain_mask.nii.gz"),
-    plot=os.path.join(get_resource_path(), "MNI152_T1_2mm.nii.gz"),
-    brain=os.path.join(get_resource_path(), "MNI152_T1_2mm_brain.nii.gz"),
-)
+
+class MNI_Template_Factory(dict):
+    """Class to build the default MNI_Template dictionary. This should never be used
+    directly, instead just `from nltools.prefs import MNI_Template` and update that
+    object's attributes to change MNI templates."""
+
+    def __init__(
+        self,
+        resolution="2mm",
+        mask_type="with_ventricles",
+        mask=os.path.join(get_resource_path(), "MNI152_T1_2mm_brain_mask.nii.gz"),
+        plot=os.path.join(get_resource_path(), "MNI152_T1_2mm.nii.gz"),
+        brain=os.path.join(get_resource_path(), "MNI152_T1_2mm_brain.nii.gz"),
+    ):
+        self._resolution = resolution
+        self._mask_type = mask_type
+        self._mask = mask
+        self._plot = plot
+        self._brain = brain
+
+        self.update(
+            {
+                "resolution": self.resolution,
+                "mask_type": self.mask_type,
+                "mask": self.mask,
+                "plot": self.plot,
+                "brain": self.brain,
+            }
+        )
+
+    @property
+    def resolution(self):
+        return self._resolution
+
+    @resolution.setter
+    def resolution(self, resolution):
+        if isinstance(resolution, (int, float)):
+            resolution = f"{int(resolution)}mm"
+        if resolution not in ["2mm", "3mm"]:
+            raise NotImplementedError(
+                "Only 2mm and 3mm resolutions are currently supported"
+            )
+        self._resolution = resolution
+        self.update({"resolution": self._resolution})
+
+    @property
+    def mask_type(self):
+        return self._mask_type
+
+    @mask_type.setter
+    def mask_type(self, mask_type):
+        if mask_type not in ["with_ventricles", "no_ventricles"]:
+            raise NotImplementedError(
+                "Only 'with_ventricles' and 'no_ventricles' mask_types are currently supported"
+            )
+        self._mask_type = mask_type
+        self.update({"mask_type": self._mask_type})
+
+    @property
+    def mask(self):
+        return self._mask
+
+    @mask.setter
+    def mask(self, mask):
+        self._mask = mask
+        self.update({"mask": self._mask})
+
+    @property
+    def plot(self):
+        return self._plot
+
+    @plot.setter
+    def plot(self, plot):
+        self._plot = plot
+        self.update({"plot": self._plot})
+
+    @property
+    def brain(self):
+        return self._brain
+
+    @brain.setter
+    def brain(self, brain):
+        self._brain = brain
+        self.update({"brain": self._brain})
+
+
+#  NOTE: We export this from the module and expect users to interact with it instead of
+#  the class constructor above
+MNI_Template = MNI_Template_Factory()
 
 
 def resolve_mni_path(MNI_Template):
@@ -64,39 +146,3 @@ def resolve_mni_path(MNI_Template):
     else:
         raise ValueError("Available templates are '2mm' or '3mm'")
     return MNI_Template
-
-
-# class Prefs(object):
-#
-#     """
-#     Prefs is a class to represent module level preferences for nltools, e.g. masks.
-#     """
-#
-#     def __init__(self):
-#         self.MNI_Template = {}
-#         self.MNI_Template['mask'] = os.path.join(get_resource_path(),'MNI152_T1_2mm_brain_mask.nii.gz')
-#         self.MNI_Template['plot']=        os.path.join(get_resource_path(),'MNI152_T1_2mm.nii.gz')
-#         self.MNI_Template['brain'] = os.path.join(get_resource_path(),'MNI152_T1_2mm_brain.nii.gz')
-#
-#     def __repr__(self):
-#         strOut = "nltools preferences:\n"
-#         for section_name in ['MNI_Template']:
-#             section = getattr(self,section_name)
-#             for key, val in list(section.items()):
-#                 strOut += "%s['%s'] = %s\n" % (section_name, key, repr(val))
-#         return strOut
-#
-#     def use_template(self,template_name):
-#         if isinstance(template_name, str):
-#             if template_name == '3mm':
-#                 self.MNI_Template['mask'] = os.path.join(get_resource_path(),'MNI152_T1_3mm_brain_mask.nii.gz')
-#                 self.MNI_Template['plot'] =        os.path.join(get_resource_path(),'MNI152_T1_3mm.nii.gz')
-#                 self.MNI_Template['brain'] = os.path.join(get_resource_path(),'MNI152_T1_3mm_brain.nii.gz')
-#             elif template_name == '2mm':
-#                 self.MNI_Template['mask'] = os.path.join(get_resource_path(),'MNI152_T1_2mm_brain_mask.nii.gz')
-#                 self.MNI_Template['plot'] =        os.path.join(get_resource_path(),'MNI152_T1_2mm.nii.gz')
-#                 self.MNI_Template['brain'] = os.path.join(get_resource_path(),'MNI152_T1_2mm_brain.nii.gz')
-#             else:
-#                 raise ValueError("Available templates are '2mm' or '3mm'")
-#         else:
-#             raise TypeError("Available templates are '2mm' or '3mm'")

nltools/tests/test_prefs.py

@@ -1,11 +1,26 @@
 from nltools.prefs import MNI_Template
 from nltools.data import Brain_Data
+import pytest
 
 
 def test_change_mni_resolution():
-    assert MNI_Template["resolution"] == "2mm"
+
+    # Defaults
     brain = Brain_Data()
     assert brain.mask.affine[1, 1] == 2.0
+    assert MNI_Template["resolution"] == "2mm"
+
+    # -> 3mm
     MNI_Template["resolution"] = "3mm"
     new_brain = Brain_Data()
     assert new_brain.mask.affine[1, 1] == 3.0
+
+    # switch back and test attribute setting
+    MNI_Template.resolution = 2.0  # floats are cool
+    assert MNI_Template["resolution"] == "2mm"
+
+    newer_brain = Brain_Data()
+    assert newer_brain.mask.affine[1, 1] == 2.0
+
+    with pytest.raises(NotImplementedError):
+        MNI_Template.resolution = 1