get_scale method

README.md

@@ -36,6 +36,16 @@ All of the color scales in colorlover
 ['rgb(252,141,89)', 'rgb(255,255,191)', 'rgb(145,191,219)']
 ```
 
+### cl.get_scale( scale_type='qual', scale_seq='Accent', length=5 )
+
+Get scales using method instead of dictionary.
+
+```
+>>> cl.get_scale('qual', 'div', 3)
+
+['rgb(127,201,127)', 'rgb(190,174,212)', 'rgb(253,192,134)']
+```
+
 ### cl.to_numeric( scale ) 
 
 Converts scale of RGB or HSL strings to list of tuples with RGB integer values

colorlover/__init__.py

@@ -1630,6 +1630,27 @@
     'rgb(189,0,38)',
     'rgb(128,0,38)']}}}
 
+def get_scale(scale_type='qual', scale_seq='Accent', length=5):
+    """return the corresponding scale without using dictionnary directly. Raise error if wrong argument
+    is givent and print available argument.
+    """
+    try:
+        assert str(length) in scales.keys()
+        try:
+            assert scale_type in scales[str(length)].keys()
+            try:
+                assert scale_seq in scales[str(length)][scale_type].keys()
+                return scales[str(length)][scale_type][scale_seq]
+
+            except AssertionError:
+                print('get_scale error : scale_type must be one of the following strings {}'.format(
+                    list(scales[str(length)][scale_type].keys())))
+        except AssertionError:
+            print('get_scale error : scale_seq must be one of the following strings {}'.format(
+                list(scales[str(length)].keys())))
+    except AssertionError:
+        print('get_scale error : length must be an integer comprised between 3 and 12')
+
 def scale_type( scale ):
     ''' returns "rbg", "hsl", "numeric", or raises exception. ie,
         [ "rgb(255, 255, 255)", "rgb(255, 255, 255)", "rgb(255, 255, 255)" ] --> "rgb" '''

tests.py

@@ -31,6 +31,12 @@ def test_scales(self):
             scales,
             ['rgb(252,141,89)', 'rgb(255,255,191)', 'rgb(145,191,219)'])
 
+    def test_get_scales(self):
+        scales = cl.get_scale(scale_type='div', scale_seq='RdYlBu', length=3)
+        self.assertEqual(
+            scales,
+            ['rgb(252,141,89)', 'rgb(255,255,191)', 'rgb(145,191,219)'])
+
     def test_to_numeric(self):
         scales = cl.to_numeric(cl.scales['3']['div']['RdYlBu'])
         self.assertEqual(