restore updated fill_between

Author: DanielGoldfarb

src/mplfinance/plotting.py

@@ -304,10 +304,8 @@ def _valid_plot_kwargs():
                                         'Description' : 'fill between specification as y-value, or sequence of'+
                                                         ' y-values, or dict containing key "y1" plus any additional'+
                                                         ' kwargs for `fill_between()`',
-                                        'Validator'   : lambda value: _num_or_seq_of_num(value) or
-                                                                     (isinstance(value,dict) and 'y1' in value and
-                                                                       _num_or_seq_of_num(value['y1']))  or
-                                                                        isinstance(value,(list,tuple))},
+                                        'Validator'   : _fill_between_validator },
+
         'tight_layout'              : { 'Default'     : False,
                                         'Description' : 'True|False implement tight layout (minimal padding around Figure)'+
                                                         ' (see also `scale_padding` kwarg)',
@@ -705,30 +703,24 @@ def plot( data, **kwargs ):
     # fill_between is NOT supported for external_axes_mode
     # (caller can easily call ax.fill_between() themselves).
     if config['fill_between'] is not None and not external_axes_mode:
-        fb    = config['fill_between']
-        panid = config['main_panel']
-        if isinstance(fb,list):
-            for element in fb:
-                if 'panel' in element:
-                    panind = element['panel']
-                    del element['panel']
-
-                element['x'] = xdates
-                ax = panels.at[panid,'axes'][0]
-                ax.fill_between(**element)
-        else:
-            if isinstance(fb,dict):
-                if 'x' in fb:
-                    raise ValueError('fill_between dict may not contain `x`')
-                if 'panel' in fb:
-                    panid = fb['panel']
-                    del fb['panel']
-            else:
-                fb = dict(y1=fb)
+        fblist = config['fill_between']
+        panid  = config['main_panel']
+        if _num_or_seq_of_num(fblist):
+            fblist = [dict(y1=fblist),]
+        elif isinstance(fblist,dict):
+            fblist = [fblist,]
+        if not _list_of_dict(fblist):
+            raise TypeError('Bad type for `fill_between` specifier.')
+        for fb in fblist:
+            if 'x' in fb:
+                raise ValueError('fill_between dict may not contain `x`')
+            if 'panel' in fb:
+                panid = fb['panel']
+                del fb['panel']
             fb['x'] = xdates
             ax = panels.at[panid,'axes'][0]
             ax.fill_between(**fb)
- 
+            
     # put the primary axis on one side,
     # and the twinx() on the "other" side:
     if not external_axes_mode: