allow addplot label to be a list when data is a dataframe

Author: DanielGoldfarb

src/mplfinance/_arg_validators.py

@@ -97,11 +97,14 @@ def _check_and_prepare_data(data, config):
 
 
 def _label_validator(label_value):
-    ''' Validates the input of label for the added plots.
-    label_value may be a str or a list of str.
+    ''' Validates the input of [legend] label for added plots.
+    label_value may be a str or a sequence of str.
     '''
     if isinstance(label_value,str):
         return True
+    if isinstance(label_value,(list,tuple,np.ndarray)):
+        if all([isinstance(v,str) for v in label_value]):
+            return True
     return False
 
 

src/mplfinance/plotting.py

@@ -777,12 +777,14 @@ def plot( data, **kwargs ):
                 else:
                     havedf = False      # must be a single series or array
                     apdata = [apdata,]  # make it iterable
+                colcount = 0
                 for column in apdata:
                     ydata = apdata.loc[:,column] if havedf else column
-                    ax = _addplot_columns(panid,panels,ydata,apdict,xdates,config)
+                    ax = _addplot_columns(panid,panels,ydata,apdict,xdates,config,colcount)
                     _addplot_apply_supplements(ax,apdict,xdates)
-                if apdict["label"]: # not supported for aptype == 'ohlc' or 'candle'
-                    contains_legend_label.append(ax)
+                    colcount += 1
+                    if apdict["label"]: # not supported for aptype == 'ohlc' or 'candle'
+                        contains_legend_label.append(ax)
         for ax in set(contains_legend_label): # there might be duplicates
             ax.legend()
 
@@ -1072,7 +1074,7 @@ def _addplot_collections(panid,panels,apdict,xdates,config):
     ax.autoscale_view()
     return ax
 
-def _addplot_columns(panid,panels,ydata,apdict,xdates,config):
+def _addplot_columns(panid,panels,ydata,apdict,xdates,config,colcount):
     external_axes_mode = apdict['ax'] is not None
     if not external_axes_mode:
         secondary_y = False
@@ -1094,7 +1096,10 @@ def _addplot_columns(panid,panels,ydata,apdict,xdates,config):
         ax = apdict['ax']
 
     aptype = apdict['type']
-    label = apdict['label']
+    if isinstance(apdict['label'],(list,tuple,np.ndarray)):
+        label = apdict['label'][colcount]
+    else: # isinstance(...,str)
+        label = apdict['label']
     if aptype == 'scatter':
         size  = apdict['markersize']
         mark  = apdict['marker']