TST: centralize and standardize pandas imports

tacaswell · tacaswell · commit e5f7982245da · 2017-12-31T18:12:38.000-05:00
Added a decorator to handle:

 - importorskip
 - using the correct unit-handler registration function to deal with:
    - pandas not auto-registering
    - pandas moving an renaming the registration function
diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -5091,11 +5091,27 @@ def test_broken_barh_empty():
     ax.broken_barh([], (.1, .5))
 
 
-def test_pandas_pcolormesh():
-    pd = pytest.importorskip('pandas')
-    from pandas.tseries import converter
-    converter.register()
+def _pandas_wrapper(func):
+    '''Decorator to centralize pandas setup / conditional import'''
+    import functools
+
+    @functools.wraps(func)
+    def wrapped_for_pandas(*args, **kwargs):
+        pytest.importorskip('pandas')
+        try:
+            from pandas.plotting import (
+                register_matplotlib_converters as register)
+        except ImportError:
+            from pandas.tseries.converter import register
+        register()
+        return func(*args, **kwargs)
+
+    return wrapped_for_pandas
 
+
+@_pandas_wrapper
+def test_pandas_pcolormesh():
+    import pandas as pd
     time = pd.date_range('2000-01-01', periods=10)
     depth = np.arange(20)
     data = np.random.rand(20, 10)
@@ -5104,10 +5120,9 @@ def test_pandas_pcolormesh():
     ax.pcolormesh(time, depth, data)
 
 
+@_pandas_wrapper
 def test_pandas_indexing_dates():
-    pd = pytest.importorskip('pandas')
-    from pandas.tseries import converter
-    converter.register()
+    import pandas as pd
 
     dates = np.arange('2005-02', '2005-03', dtype='datetime64[D]')
     values = np.sin(np.array(range(len(dates))))
@@ -5119,10 +5134,9 @@ def test_pandas_indexing_dates():
     ax.plot('dates', 'values', data=without_zero_index)
 
 
+@_pandas_wrapper
 def test_pandas_errorbar_indexing():
-    pd = pytest.importorskip('pandas')
-    from pandas.tseries import converter
-    converter.register()
+    import pandas as pd
 
     df = pd.DataFrame(np.random.uniform(size=(5, 4)),
                       columns=['x', 'y', 'xe', 'ye'],
@@ -5131,30 +5145,28 @@ def test_pandas_errorbar_indexing():
     ax.errorbar('x', 'y', xerr='xe', yerr='ye', data=df)
 
 
+@_pandas_wrapper
 def test_pandas_indexing_hist():
-    pd = pytest.importorskip('pandas')
-    from pandas.tseries import converter
-    converter.register()
+    import pandas as pd
 
     ser_1 = pd.Series(data=[1, 2, 2, 3, 3, 4, 4, 4, 4, 5])
     ser_2 = ser_1.iloc[1:]
     fig, axes = plt.subplots()
     axes.hist(ser_2)
 
 
+@_pandas_wrapper
 def test_pandas_bar_align_center():
     # Tests fix for issue 8767
-    pd = pytest.importorskip('pandas')
-    from pandas.tseries import converter
-    converter.register()
+    import pandas as pd
 
     df = pd.DataFrame({'a': range(2), 'b': range(2)})
 
     fig, ax = plt.subplots(1)
 
-    rect = ax.bar(df.loc[df['a'] == 1, 'b'],
-                  df.loc[df['a'] == 1, 'b'],
-                  align='center')
+    ax.bar(df.loc[df['a'] == 1, 'b'],
+           df.loc[df['a'] == 1, 'b'],
+           align='center')
 
     fig.canvas.draw()
 
