Move optional spatial support to own module.

elevation/cli.py

@@ -23,6 +23,12 @@
 
 import elevation
 from . import util
+# NOTE: GDAL/OGR bindings are not supported on Pypy so the -r/--reference option is disabled
+try:
+    from .spatial import import_bounds
+except ImportError:
+    def import_bounds(reference):
+        raise click.BadOptionUsage("-r/--reference disabled, to enable it install rasterio and fiona.")
 
 
 # disable overzealous warning
@@ -69,31 +75,12 @@ def seed(**kwargs):
     elevation.seed(**kwargs)
 
 
-try:
-    # NOTE: GDAL/OGR bindings are not supported on Pypy
-    import rasterio
-    import fiona
-
-    def import_bounds(reference):
-        # ASSUMPTION: rasterio and fiona bounds are given in geodetic WGS84 crs
-        try:
-            with rasterio.open(reference) as datasource:
-                bounds = datasource.bounds
-        except:
-            with fiona.open(reference) as datasource:
-                bounds = datasource.bounds
-        return bounds
-except ImportError:
-    def import_bounds(reference):
-        raise click.BadOptionUsage("-r/--reference disabled, to enable it install rasterio and fiona.")
-
-
 def ensure_bounds(wrapped):
     @functools.wraps(wrapped)
     def wrapper(bounds, reference, **kwargs):
         if not bounds:
             if not reference:
-                raise ValueError("bounds are not defined.")
+                raise click.BadOptionUsage("One of --bounds or --reference must be supplied.")
             else:
                 bounds = import_bounds(reference)
         return wrapped(bounds=bounds, **kwargs)

elevation/spatial.py

@@ -0,0 +1,32 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2016 B-Open Solutions srl - http://bopen.eu
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# python 2 support via python-future
+from __future__ import absolute_import, division, print_function, unicode_literals
+
+import rasterio
+import fiona
+
+
+def import_bounds(reference):
+    # ASSUMPTION: rasterio and fiona bounds are given in geodetic WGS84 crs
+    try:
+        with rasterio.open(reference) as datasource:
+            bounds = datasource.bounds
+    except:
+        with fiona.open(reference) as datasource:
+            bounds = datasource.bounds
+    return bounds