Fix to support cdflib v1.0 (#94)

* Fix to support cdflib v1.0

* Replace generic exception with FileExistsError

Author: smithara

docs/release_notes.rst

@@ -4,6 +4,11 @@ Release notes
 Change log
 ----------
 
+Changes from 0.11.1 to 0.11.2
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+- Fix support for cdflib version 1.0
+
 Changes from 0.11.0 to 0.11.1
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 

src/viresclient/_data_handling.py

@@ -100,7 +100,7 @@ def __init__(self, file, filetype="cdf"):
                 globalatts.get("MAGNETIC_MODELS", [])
             )
             self.data_filters = self._ensure_list(globalatts.get("DATA_FILTERS", []))
-            self.variables = self._cdf.cdf_info()["zVariables"]
+            self.variables = self._get_attr_or_key(self._cdf.cdf_info(), "zVariables")
             self._varatts = {var: self._cdf.varattsget(var) for var in self.variables}
             self._varinfo = {var: self._cdf.varinq(var) for var in self.variables}
         else:
@@ -110,7 +110,10 @@ def __enter__(self):
         return self
 
     def __exit__(self, *args):
-        self._cdf.close()
+        try:
+            self._cdf.close()
+        except AttributeError:
+            pass
 
     @staticmethod
     def _open_cdf(file):
@@ -130,6 +133,15 @@ def _ensure_list(attribute):
         else:
             return attribute
 
+    @staticmethod
+    def _get_attr_or_key(obj, attr):
+        # Used to work around cdflib<1 & >=1 support
+        # cdflib>=1 introduces dataclasses in place of some dicts
+        if isinstance(obj, dict):
+            return obj.get(attr, None)
+        else:
+            return getattr(obj, attr, None)
+
     def get_variable(self, var):
         try:
             data = self._cdf.varget(var)
@@ -149,10 +161,10 @@ def get_variable_description(self, var):
         return desc if desc else catdesc
 
     def get_variable_numdims(self, var):
-        return self._varinfo[var].get("Num_Dims")
+        return self._get_attr_or_key(self._varinfo[var], "Num_Dims")
 
     def get_variable_dimsizes(self, var):
-        return self._varinfo[var].get("Dim_Sizes")
+        return self._get_attr_or_key(self._varinfo[var], "Dim_Sizes")
 
     @staticmethod
     def _cdftime_to_datetime(t):
@@ -467,7 +479,9 @@ def _check_outfile(path, path_extension, overwrite=False):
         if path.split(".")[-1].lower() != path_extension:
             raise TypeError(f"Filename extension should be {path_extension}")
         if os.path.isfile(path) and not overwrite:
-            raise Exception("File not written as it already exists and overwrite=False")
+            raise FileExistsError(
+                "File not written as it already exists and overwrite=False"
+            )
 
     def to_file(self, path, overwrite=False):
         """Saves the data to the specified file.

tests/test_ReturnedData.py

@@ -85,8 +85,7 @@ def test_ReturnedDataFile_saving(tmpfile):
         # Check that not overwriting and overwriting work right
         testfile = str(tmpfile(f"testfile.{filetype}"))
         retdata.to_file(testfile)
-        # with pytest.raises(FileExistsError):  # not in py27
-        with pytest.raises(Exception):
+        with pytest.raises(FileExistsError):
             retdata.to_file(testfile, overwrite=False)
         retdata.to_file(testfile, overwrite=True)
 
@@ -115,14 +114,13 @@ def test_ReturnedData_saving(tmpfile):
         # Check that not overwriting and overwriting work right
         testfile = str(tmpfile(f"testfile.{filetype}"))
         retdata.to_file(testfile)
-        # with pytest.raises(FileExistsError):  # not in py27
-        with pytest.raises(Exception):
+        with pytest.raises(FileExistsError):
             retdata.to_file(testfile, overwrite=False)
         retdata.to_file(testfile, overwrite=True)
         # repeat for .to_files()
         testfile = str(tmpfile(f"testfile2.{filetype}"))
         retdata.to_files([testfile])
-        with pytest.raises(Exception):
+        with pytest.raises(FileExistsError):
             retdata.to_files([testfile], overwrite=False)
         retdata.to_files([testfile], overwrite=True)