Reject raw_data_location=None with a clear UserInputError

src/nemosis/data_fetch_methods.py

@@ -63,6 +63,10 @@ def dynamic_data_compiler(
     Returns:
         all_data (pd.Dataframe): All data concatenated.
     """
+
+    if raw_data_location is None:
+        raise UserInputError("The raw_data_location provided is None.")
+
     if not _os.path.isdir(raw_data_location):
         raise UserInputError("The raw_data_location provided does not exist.")
 
@@ -186,6 +190,10 @@ def cache_compiler(
     Returns:
         Nothing
     """
+
+    if raw_data_location is None:
+        raise UserInputError("The raw_data_location provided is None.")
+
     if not _os.path.isdir(raw_data_location):
         raise UserInputError("The raw_data_location provided does not exist.")
 
@@ -262,6 +270,9 @@ def static_table(
     Returns:
         data (pd.Dataframe)
     """
+    if raw_data_location is None:
+        raise UserInputError("The raw_data_location provided is None.")
+
     if not _os.path.isdir(raw_data_location):
         raise UserInputError("The raw_data_location provided does not exist.")
 

tests/test_errors.py

@@ -71,6 +71,17 @@ def test_dynamic_select_columns_all_requires_csv(nemosis_fixture):
         )
 
 
+def test_dynamic_raw_data_location_is_none():
+    """Passing None as the cache path is a common caller mistake (forgot
+    to set it, config returned None). Reject with UserInputError rather
+    than the cryptic TypeError that os.path.isdir(None) would raise."""
+    with pytest.raises(UserInputError, match="is None"):
+        dynamic_data_compiler(
+            "2018/05/01 00:00:00", "2018/05/01 01:00:00",
+            "DISPATCHPRICE", raw_data_location=None,
+        )
+
+
 # ---------------------------------------------------------------------------
 # Argument-validation: cache_compiler
 # ---------------------------------------------------------------------------
@@ -102,6 +113,14 @@ def test_cache_select_columns_requires_rebuild(nemosis_fixture):
         )
 
 
+def test_cache_raw_data_location_is_none():
+    with pytest.raises(UserInputError, match="is None"):
+        cache_compiler(
+            "2018/05/01 00:00:00", "2018/05/01 01:00:00",
+            "DISPATCHPRICE", raw_data_location=None,
+        )
+
+
 # ---------------------------------------------------------------------------
 # Argument-validation: static_table
 # ---------------------------------------------------------------------------
@@ -121,6 +140,11 @@ def test_static_filter_col_not_in_select_columns(nemosis_fixture):
         )
 
 
+def test_static_raw_data_location_is_none():
+    with pytest.raises(UserInputError, match="is None"):
+        static_table("VARIABLES_FCAS_4_SECOND", raw_data_location=None)
+
+
 # ---------------------------------------------------------------------------
 # Network / availability: NoDataToReturn
 # ---------------------------------------------------------------------------