a signature-preserving decorator using wrapt package

closes #363

Author: OlegShteynbuk

.travis.yml

@@ -51,7 +51,7 @@ install:
   - conda update -q conda
   # Useful for debugging any issues with conda
   - conda info -a
-  - conda create -q -n test-environment python=$PYTHON coverage setuptools html5lib lxml pytest pytest-cov
+  - conda create -q -n test-environment python=$PYTHON coverage setuptools html5lib lxml pytest pytest-cov wrapt
   - source activate test-environment
   - if [[ "$PANDAS" == "MASTER" ]]; then
       conda install numpy pytz python-dateutil;

pandas_datareader/_testing.py

@@ -2,7 +2,7 @@
 Utilities for testing purposes.
 """
 
-from functools import wraps
+import wrapt
 
 
 def skip_on_exception(exp):
@@ -11,22 +11,20 @@ def skip_on_exception(exp):
     the Exception is raised for reasons beyond our control (e.g.
     flakey 3rd-party API).
 
+    a signature-preserving decorator
+
     Parameters
     ----------
     exp : The Exception under which to execute try-except.
     """
 
     from pytest import skip
 
-    def outer_wrapper(f):
-
-        @wraps(f)
-        def wrapper(*args, **kwargs):
-            try:
-                f(*args, **kwargs)
-            except exp as e:
-                skip(str(e))
-
-        return wrapper
+    @wrapt.decorator
+    def wrapper(wrapped, instance, args, kwargs):
+        try:
+            return wrapped(*args, **kwargs)
+        except exp as e:
+            skip(str(e))
 
-    return outer_wrapper
+    return wrapper

pandas_datareader/tests/yahoo/test_yahoo.py

@@ -132,17 +132,12 @@ def test_get_data_multiple_symbols(self):
         web.get_data_yahoo(sl, '2012')
 
     @pytest.mark.parametrize('adj_pr', [True, False])
+    @skip_on_exception(RemoteDataError)
     def test_get_data_null_as_missing_data(self, adj_pr):
-        # TODO: We can't decorate the test function along with
-        # parametrization because it errors.  Investigate this later.
-        @skip_on_exception(RemoteDataError)
-        def null_as_missing_data(adj_price):
-            result = web.get_data_yahoo('SRCE', '20160626', '20160705',
-                                        adjust_price=adj_pr)
-            # sanity checking
-            assert result.dtypes.all() == np.floating
-
-        null_as_missing_data(adj_pr)
+        result = web.get_data_yahoo('SRCE', '20160626', '20160705',
+                                    adjust_price=adj_pr)
+        # sanity checking
+        assert result.dtypes.all() == np.floating
 
     @skip_on_exception(RemoteDataError)
     def test_get_data_multiple_symbols_two_dates(self):

tox.ini

@@ -7,3 +7,4 @@ commands=
 deps=
     pytest
     pytest-cov
+    wrapt