Catch KeyError when parameters is requested as class property (#169)

src/fmu/ensemble/ensemble.py

@@ -292,7 +292,7 @@ def remove_data(self, localpaths):
         on each realization in the ensemble.
 
         Args:
-            localpath (string): Full localpath to
+            localpaths (string): Full localpaths to
                 the data, or list of strings.
         """
         if isinstance(localpaths, str):
@@ -412,8 +412,18 @@ def manifest(self, manifest):
 
     @property
     def parameters(self):
-        """Getter for get_parameters(convert_numeric=True)"""
-        return self.load_txt("parameters.txt")
+        """Build a dataframe of the information in each
+        realizations parameters.txt.
+
+        If no realizations have the file, an empty dataframe is returned.
+
+        Returns:
+            pd.DataFrame
+        """
+        try:
+            return self.load_txt("parameters.txt")
+        except KeyError:
+            return pd.DataFrame()
 
     def load_scalar(self, localpath, convert_numeric=False, force_reread=False):
         """Parse a single value from a file for each realization.

src/fmu/ensemble/ensemblecombination.py

@@ -331,7 +331,10 @@ def get_volumetric_rates(
     @property
     def parameters(self):
         """Return parameters from the ensemble as a class property"""
-        return self.get_df("parameters.txt")
+        try:
+            return self.get_df("parameters.txt")
+        except KeyError:
+            return pd.DataFrame()
 
     def __len__(self):
         """Estimate the number of realizations in this

src/fmu/ensemble/ensembleset.py

@@ -336,8 +336,18 @@ def add_ensemble(self, ensembleobject):
 
     @property
     def parameters(self):
-        """Getter for ensemble.parameters(convert_numeric=True)"""
-        return self.get_df("parameters.txt")
+        """Build a dataframe of the information in each
+        realizations parameters.txt.
+
+        If no realizations have the file, an empty dataframe is returned.
+
+        Returns:
+            pd.DataFrame
+        """
+        try:
+            return self.get_df("parameters.txt")
+        except KeyError:
+            return pd.DataFrame()
 
     def load_scalar(self, localpath, convert_numeric=False, force_reread=False):
         """Parse a single value from a file
@@ -438,6 +448,22 @@ def drop(self, localpath, **kwargs):
             except ValueError:
                 pass  # Allow localpath to be missing in some ensembles.
 
+    def remove_data(self, localpaths):
+        """Remove certain datatypes from each ensembles/realizations
+        datastores. This modifies the underlying realization
+        objects, and is equivalent to
+
+            >>> del realization[localpath]
+
+        on each realization in each ensemble.
+
+        Args:
+            localpaths (string): Full localpath to
+                the data, or list of strings.
+        """
+        for _, ensemble in self._ensembles.items():
+            ensemble.remove_data(localpaths)
+
     def process_batch(self, batch=None):
         """Process a list of functions to run/apply
 

tests/test_ensemble.py

@@ -180,6 +180,30 @@ def test_reek001(tmpdir):
     assert len(reekensemble.keys()) == keycount - 1
 
 
+def test_noparameters():
+    """Test what happens when parameters.txt is missing"""
+
+    testdir = os.path.dirname(os.path.abspath(__file__))
+    reekensemble = ScratchEnsemble(
+        "reektest", testdir + "/data/testensemble-reek001/" + "realization-*/iter-0"
+    )
+    # Parameters.txt exist on disk, so it is loaded:
+    assert not reekensemble.parameters.empty
+    # Remove it each realization:
+    reekensemble.remove_data("parameters.txt")
+    assert reekensemble.parameters.empty
+
+    # However, when parameters.txt is excplicitly asked for,
+    # an exception should be raised:
+    with pytest.raises(KeyError):
+        reekensemble.get_df("parameters.txt")
+
+    reekensemble.load_smry(time_index="yearly", column_keys="FOPT")
+    assert not reekensemble.get_df("unsmry--yearly").empty
+    with pytest.raises(KeyError):
+        reekensemble.get_df("unsmry--yearly", merge="parameters.txt")
+
+
 def test_emptyens():
     """Check that we can initialize an empty ensemble"""
     ens = ScratchEnsemble("emptyens")

tests/test_ensembleset.py

@@ -281,6 +281,35 @@ def rms_vol2df(kwargs):
     assert len(ensset5.get_df("unsmry--daily")) == 10980
 
 
+def test_noparameters(tmpdir):
+    testdir = os.path.dirname(os.path.abspath(__file__))
+    ensdir = os.path.join(testdir, "data/testensemble-reek001/")
+
+    tmpdir.chdir()
+    symlink_iter(ensdir, "iter-0")
+    symlink_iter(ensdir, "iter-1")
+
+    iter0 = ScratchEnsemble("iter-0", str(tmpdir.join("realization-*/iter-0")))
+    iter1 = ScratchEnsemble("iter-1", str(tmpdir.join("realization-*/iter-1")))
+
+    ensset = EnsembleSet("reek001", [iter0, iter1])
+    assert not ensset.parameters.empty
+
+    # Remove it each realization:
+    ensset.remove_data("parameters.txt")
+    assert ensset.parameters.empty
+
+    # However, when parameters.txt is excplicitly asked for,
+    # an exception should be raised:
+    with pytest.raises(KeyError):
+        ensset.get_df("parameters.txt")
+
+    ensset.load_smry(time_index="yearly", column_keys="FOPT")
+    assert not ensset.get_df("unsmry--yearly").empty
+    with pytest.raises(KeyError):
+        ensset.get_df("unsmry--yearly", merge="parameters.txt")
+
+
 def test_pred_dir(tmpdir):
     """Test import of a stripped 5 realization ensemble,
     manually doubled to two identical ensembles,