Merge pull request #338 from shoyer/truncate-long-atrs

Truncate long attributes when printing datasets

Author: shoyer

doc/api.rst

@@ -77,6 +77,7 @@ Comparisons
 
    Dataset.equals
    Dataset.identical
+   Dataset.broadcast_equals
 
 Indexing
 --------
@@ -236,6 +237,7 @@ Comparisons
 
    DataArray.equals
    DataArray.identical
+   DataArray.broadcast_equals
 
 IO / Conversion
 ===============

doc/examples/monthly-means.rst

@@ -1,3 +1,5 @@
+.. _monthly means example:
+
 Calculating Seasonal Averages from Timeseries of Monthly Means
 ==============================================================
 

doc/whats-new.rst

@@ -116,12 +116,13 @@ Enhancements
 - Consolidated the functionality of ``dumps`` (writing a dataset to a netCDF3
   bytestring) into :py:meth:`~xray.Dataset.to_netcdf` (:issue:`333`).
 - :py:meth:`~xray.Dataset.to_netcdf` now supports writing to groups in netCDF4
-  files (:issue:`333`). It also now has a full docstring -- you should read it!
+  files (:issue:`333`). It also finally has a full docstring -- you should read
+  it!
 - :py:func:`~xray.open_dataset` and :py:meth:`~xray.Dataset.to_netcdf` now
   work on netCDF4 files when netcdf4-python is not installed as long as scipy
   is available (:issue:`333`).
-- The new :py:meth:`xray.Dataset.drop <Dataset.drop>` and
-  :py:meth:`xray.DataArray.drop <DataArray.drop>` methods makes it easy to drop
+- The new :py:meth:`Dataset.drop <xray.Dataset.drop>` and
+  :py:meth:`DataArray.drop <xray.DataArray.drop>` methods makes it easy to drop
   explicitly listed variables or index labels:
 
   .. ipython:: python
@@ -134,9 +135,13 @@ Enhancements
       arr = xray.DataArray([1, 2, 3], coords=[('x', list('abc'))])
       arr.drop(['a', 'c'], dim='x')
 
-- The :py:meth:`~xray.Dataset.broadcast_equals` has been added to correspond to
+- :py:meth:`~xray.Dataset.broadcast_equals` has been added to correspond to
   the new ``compat`` option.
-- TODO: added a documentation example by Joe Hamman.
+- Long attributes are now truncated at 500 characters when printing a dataset
+  (:issue:`338`). This should make things more convenient for working with
+  datasets interactively.
+- Added a new documentation example, :ref:`monthly means example`. Thanks Joe
+  Hamman!
 
 Bug fixes
 ~~~~~~~~~

xray/core/formatting.py

@@ -143,9 +143,16 @@ def summarize_coord(name, var, col_width):
     return _summarize_var_or_coord(name, var, col_width, show_values, marker)
 
 
+def _maybe_truncate(obj, maxlen=500):
+    s = str(obj)
+    if len(s) > maxlen:
+        s = s[:(maxlen - 3)] + '...'
+    return s
+
+
 def summarize_attr(key, value, col_width=None):
     # ignore col_width for now to more clearly distinguish attributes
-    return '    %s: %s' % (key, value)
+    return '    %s: %s' % (key, _maybe_truncate(value))
 
 
 EMPTY_REPR = '    *empty*'

xray/test/test_dataset.py

@@ -103,6 +103,10 @@ def test_repr(self):
         print(actual)
         self.assertEqual(expected, actual)
 
+        # verify long attributes are truncated
+        data = Dataset(attrs={'foo': 'bar' * 1000})
+        self.assertTrue(len(repr(data)) < 1000)
+
     def test_constructor(self):
         x1 = ('x', 2 * np.arange(100))
         x2 = ('x', np.arange(1000))