BUG: close 872, DataFrame.to_string formatters on integers

Author: lodagro

pandas/core/format.py

@@ -516,9 +516,14 @@ def get_result(self):
 
 class IntArrayFormatter(GenericArrayFormatter):
 
-
     def get_result(self):
-        fmt_values = ['% d' % x for x in self.values]
+        if self.formatter:
+            formatter = self.formatter
+        else:
+            formatter = lambda x: '% d' % x
+
+        fmt_values = [formatter(x) for x in self.values]
+
         return _make_fixed_width(fmt_values, self.justify)
 
 

pandas/tests/test_format.py

@@ -88,6 +88,20 @@ def test_to_string_unicode_three(self):
         buf = StringIO()
         dm.to_string(buf)
 
+    def test_to_string_with_formatters(self):
+        df = DataFrame({'int': [1, 2, 3],
+                        'float': [1.0, 2.0, 3.0],
+                        'object': [(1,2), True, False]},
+                        columns=['int', 'float', 'object'])
+
+        result = df.to_string(formatters={'int': lambda x: '0x%x' % x,
+                                          'float': lambda x: '[% 4.1f]' % x,
+                                          'object': lambda x: '-%s-' % str(x)})
+        self.assertEqual(result, ('  int  float    object\n'
+                                  '0 0x1 [ 1.0]  -(1, 2)-\n'
+                                  '1 0x2 [ 2.0]    -True-\n'
+                                  '2 0x3 [ 3.0]   -False-'))
+
     def test_to_string_with_formatters_unicode(self):
         df = DataFrame({u'c/\u03c3':[1,2,3]})
         result = df.to_string(formatters={u'c/\u03c3': lambda x: '%s' % x})