Squeeze blank lines in RecipeOrganizer.show().

Avoid long sections of blank lines in filtered output.
Also simplify the unit test of RecipeOrganizer.show.

Author: pavoljuhas

diffpy/srfit/fitbase/recipeorganizer.py

@@ -25,7 +25,7 @@
 
 from numpy import inf
 from collections import OrderedDict
-from itertools import chain, ifilter
+from itertools import chain, ifilter, groupby
 import re
 
 from diffpy.srfit.fitbase.constraint import Constraint
@@ -970,7 +970,14 @@ def show(self, pattern="", textwidth=78):
         tlines = self._formatManaged()
         if tlines:
             lines.extend(["Parameters", _DASHEDLINE])
-            lines.extend(filter(pmatch, tlines))
+            linesok = filter(pmatch, tlines)
+            lastnotblank = False
+            # squeeze repeated blank lines
+            for lastnotblank, g in groupby(linesok, bool):
+                lines.extend(g if lastnotblank else [""])
+            # remove trailing blank line
+            if not lastnotblank:
+                lines.pop(-1)
 
         # FIXME - parameter names in equations not particularly informative
         # Show constraints

diffpy/srfit/tests/testrecipeorganizer.py

@@ -509,47 +509,50 @@ def test_releaseOldEquations(self):
     def test_show(self):
         """Verify output from the show function.
         """
-        sys.stdout = cStringIO.StringIO()
-        self.m.show()
-        self.assertEqual('', sys.stdout.getvalue())
-        sys.stdout = cStringIO.StringIO()
+        def capture_show(*args, **kwargs):
+            sys.stdout = cStringIO.StringIO()
+            self.m.show(*args, **kwargs)
+            rv = sys.stdout.getvalue()
+            sys.stdout = sys.__stdout__
+            return rv
+        self.assertEqual('', capture_show())
         self.m._newParameter('x', 1)
         self.m._newParameter('y', 2)
-        self.m.show()
-        out1 = sys.stdout.getvalue()
+        out1 = capture_show()
         lines1 = out1.strip().split('\n')
         self.assertEqual(4, len(lines1))
         self.assertTrue('Parameters' in lines1)
         self.assertFalse('Constraints' in lines1)
         self.assertFalse('Restraints' in lines1)
         self.m._newParameter('z', 7)
         self.m.constrain('y', '3 * z')
-        sys.stdout = cStringIO.StringIO()
-        self.m.show()
-        out2 = sys.stdout.getvalue()
+        out2 = capture_show()
         lines2 = out2.strip().split('\n')
         self.assertEqual(9, len(lines2))
         self.assertTrue('Parameters' in lines2)
         self.assertTrue('Constraints' in lines2)
         self.assertFalse('Restraints' in lines2)
         self.m.restrain('z', lb=2, ub=3, sig=0.001)
-        sys.stdout = cStringIO.StringIO()
-        self.m.show()
-        out3 = sys.stdout.getvalue()
+        out3 = capture_show()
         lines3 = out3.strip().split('\n')
         self.assertEqual(13, len(lines3))
         self.assertTrue('Parameters' in lines3)
         self.assertTrue('Constraints' in lines3)
         self.assertTrue('Restraints' in lines3)
-        sys.stdout = cStringIO.StringIO()
-        self.m.show(pattern='x')
-        out4 = sys.stdout.getvalue()
+        out4 = capture_show(pattern='x')
         lines4 = out4.strip().split('\n')
         self.assertEqual(9, len(lines4))
-        sys.stdout = cStringIO.StringIO()
-        self.m.show(pattern='^')
-        out5 = sys.stdout.getvalue()
+        out5 = capture_show(pattern='^')
         self.assertEqual(out3, out5)
+        # check output with another level of hierarchy
+        self.m._addObject(RecipeOrganizer("foo"), self.m._containers)
+        self.m.foo._newParameter("bar", 13)
+        out6 = capture_show()
+        self.assertTrue("foo.bar" in out6)
+        # filter out foo.bar
+        out7 = capture_show('^(?!foo).')
+        self.assertFalse("foo.bar" in out7)
+        self.assertEqual(out3, out7)
         return
 
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