matplotlib · ivanov · Apr 18, 2013 · Mar 27, 2013 · Mar 28, 2013 · Apr 12, 2013
diff --git a/doc/users/whats_new.rst b/doc/users/whats_new.rst
@@ -110,6 +110,21 @@ used, which, in the case of straight contours was sometimes quite distant
 from the requested location. Much more precise label positioning is now
 possible.
 
+Quickly find rcParams
+---------------------
+Phil Elson made it easier to search for rcParameters by passing a
+valid regular expression to :func:`matplotlib.RcParams.find_all`.
+:class:`matplotlib.RcParams` now also has a pretty repr and str representation
+so that search results are printed prettily:
+
+    >>> import matplotlib
+    >>> print(matplotlib.rcParams.find_all('\.size'))
    RcParams({'font.size': 12,
+              'xtick.major.size': 4,
+              'xtick.minor.size': 2,
+              'ytick.major.size': 4,
+              'ytick.minor.size': 2})
+
 .. _whats-new-1-2-2:
 
 new in matplotlib 1.2.2

diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -706,8 +706,8 @@ class RcParams(dict):
     :mod:`matplotlib.rcsetup`
     """
 
-    validate = dict([ (key, converter) for key, (default, converter) in \
-                     defaultParams.iteritems() ])
+    validate = dict((key, converter) for key, (default, converter) in \
+                     defaultParams.iteritems())
     msg_depr = "%s is deprecated and replaced with %s; please use the latter."
     msg_depr_ignore = "%s is deprecated and ignored. Use %s"
 
@@ -738,6 +738,19 @@ def __getitem__(self, key):
             key = alt
         return dict.__getitem__(self, key)
 
+    def __repr__(self):
+        import pprint
+        class_name = self.__class__.__name__
+        indent = len(class_name) + 1
+        repr_split = pprint.pformat(dict(self), indent=1,
+                                    width=80 - indent).split('\n')
+        repr_indented = ('\n' + ' ' * indent).join(repr_split)
+        return '{0}({1})'.format(class_name, repr_indented)
+
+    def __str__(self):
+        return '\n'.join('{0}: {1}'.format(k, v)
+                         for k, v in sorted(self.items()))
+
     def keys(self):
         """
         Return sorted list of keys.
@@ -750,7 +763,25 @@ def values(self):
         """
         Return values in order of sorted keys.
         """
-        return [self[k] for k in self.iterkeys()]
+        return [self[k] for k in self.keys()]
+
+    def find_all(self, pattern):
+        """
+        Return the subset of this RcParams dictionary whose keys match,
+        using :func:`re.search`, the given ``pattern``.
+
+        .. note::
+
+            Changes to the returned dictionary are *not* propagated to
+            the parent RcParams dictionary.
+
+        """
+        import re
+        pattern_re = re.compile(pattern)
+        return RcParams((key, value)
+                        for key, value in self.items()
+                        if pattern_re.search(key))
+
 
 def rc_params(fail_on_error=False):
     'Return the default params updated from the values in the rc file'

diff --git a/lib/matplotlib/tests/__init__.py b/lib/matplotlib/tests/__init__.py
@@ -1,8 +1,12 @@
 from __future__ import print_function
 from matplotlib import rcParams, rcdefaults, use
 
+import difflib
+
+
 _multiprocess_can_split_ = True
 
+
 def setup():
     use('Agg', warn=False) # use Agg backend for these tests
 
@@ -13,3 +17,19 @@ def setup():
     rcParams['font.family'] = 'Bitstream Vera Sans'
     rcParams['text.hinting'] = False
     rcParams['text.hinting_factor'] = 8
+
+
+def assert_str_equal(reference_str, test_str,
+                     format_str='String {str1} and {str2} do not match:\n{differences}'):
+    """
+    Assert the two strings are equal. If not, fail and print their diffs using difflib.
+
+    """
+    if reference_str != test_str:
+        diff = difflib.unified_diff(reference_str.splitlines(1),
+                                    test_str.splitlines(1),
+                                    'Reference', 'Test result',
+                                    '', '', 0)
+        raise ValueError(format_str.format(str1=reference_str,
+                                           str2=test_str,
+                                           differences=''.join(diff)))
diff --git a/lib/matplotlib/tests/test_rcparams.py b/lib/matplotlib/tests/test_rcparams.py
@@ -1,6 +1,9 @@
 import os
 
 import matplotlib as mpl
+from matplotlib.tests import assert_str_equal
+
+
 mpl.rc('text', usetex=False)
 mpl.rc('lines', linewidth=22)
 
@@ -34,5 +37,39 @@ def test_rcparams():
         mpl.rcParams['lines.linewidth'] = linewidth
 
 
+def test_RcParams_class():
+    rc = mpl.RcParams({'font.cursive': ['Apple Chancery',
+                                        'Textile',
+                                        'Zapf Chancery',
+                                        'cursive'],
+                       'font.family': 'sans-serif',
+                       'font.weight': 'normal',
+                       'font.size': 12})
+
+
+    expected_repr = """
+RcParams({'font.cursive': ['Apple Chancery',
+                           'Textile',
+                           'Zapf Chancery',
+                           'cursive'],
+          'font.family': 'sans-serif',
+          'font.size': 12,
+          'font.weight': 'normal'})""".lstrip()
+
+    assert_str_equal(expected_repr, repr(rc))
+
+    expected_str = """
+font.cursive: ['Apple Chancery', 'Textile', 'Zapf Chancery', 'cursive']
+font.family: sans-serif
+font.size: 12
+font.weight: normal""".lstrip()
+
+    assert_str_equal(expected_str, str(rc))
+
+    # test the find_all functionality
+    assert ['font.cursive', 'font.size'] == sorted(rc.find_all('i[vz]').keys())
+    assert ['font.family'] == rc.find_all('family').keys()
+
 if __name__ == '__main__':
-    test_rcparams()
+    import nose
+    nose.runmodule(argv=['-s', '--with-doctest'], exit=False)