Add utility function to check for ‘data’ type.

* is the type ‘data’
* is it ‘style’, but as an array?

Author: theengineear

plotly/graph_objs/graph_objs_tools.py

@@ -226,3 +226,36 @@ def curtail_val_repr(val, max_chars, add_delim=False):
     if add_delim:
         r += delim
     return r
+
+
+def value_is_data(obj_name, key, value):
+    """
+    Values have types associated with them based on graph_reference.
+
+    'data' type values are always kept
+    'style' values are kept if they're sequences (but not strings)
+
+    :param (str) obj_name: E.g., 'scatter', 'figure'
+    :param (str) key: E.g., 'x', 'y', 'text'
+    :param (*) value:
+    :returns: (bool)
+
+    """
+    try:
+        key_type = INFO[obj_name]['keymeta'][key]['key_type']
+    except KeyError:
+        return False
+
+    if key_type not in ['data', 'style']:
+        return False
+
+    if key_type == 'data':
+        return True
+
+    if key_type == 'style':
+        iterable = hasattr(value, '__iter__')
+        stringy = isinstance(value, six.string_types)
+        dicty = isinstance(value, dict)
+        return iterable and not stringy and not dicty
+
+    return False

plotly/tests/test_core/test_graph_objs/test_graph_objs_tools.py

@@ -0,0 +1,29 @@
+from __future__ import absolute_import
+
+from unittest import TestCase
+
+try:
+    from collections import OrderedDict
+except ImportError:
+    from ordereddict import OrderedDict
+
+from plotly.graph_objs.graph_objs_tools import value_is_data
+
+
+class TestValueIsData(TestCase):
+
+    def test_unknown_strings(self):
+        self.assertFalse(value_is_data('scatter', 'blah', ''))
+        self.assertFalse(value_is_data('huh?', 'text', None))
+
+    def test_data_value_type(self):
+        self.assertTrue(value_is_data('scatter', 'x', {}))
+        self.assertTrue(value_is_data('bar', 'name', 'bill'))
+        self.assertTrue(value_is_data('histogram', 'x', [5, 5]))
+        self.assertTrue(value_is_data('xaxis', 'range', [0, 5]))
+
+    def test_style_value_type(self):
+        self.assertFalse(value_is_data('marker', 'color', 'red'))
+        self.assertTrue(value_is_data('marker', 'color', ['red', 'blue']))
+        self.assertTrue(value_is_data('marker', 'opacity', (.9, .5)))
+        self.assertFalse(value_is_data('marker', 'symbol', {}))