Fix timezone bug (issue 236)

Author: DanielGoldfarb

examples/scratch_pad/issues/issue#236_timezone_bug.ipynb

@@ -40,7 +40,10 @@ def _check_and_prepare_data(data, config):
     o, h, l, c, v = columns
     cols = [o, h, l, c]
 
-    dates   = mdates.date2num(data.index.to_pydatetime())
+    if config['tz_localize']:
+        dates   = mdates.date2num(data.index.tz_localize(None).to_pydatetime())
+    else:  # Just in case someone was depending on this bug (Issue 236)
+        dates   = mdates.date2num(data.index.to_pydatetime())
     opens   = data[o].values
     highs   = data[h].values
     lows    = data[l].values

examples/scratch_pad/issues/issue236_timezone_bug.ipynb

@@ -1,5 +1,5 @@
 
-version_info = (0, 12, 7, 'alpha', 3)
+version_info = (0, 12, 7, 'alpha', 4)
 
 _specifier_ = {'alpha': 'a','beta': 'b','candidate': 'rc','final': ''}
 

src/mplfinance/_arg_validators.py

@@ -256,6 +256,9 @@ def _valid_plot_kwargs():
 
         'volume_exponent'           : { 'Default'     : None,
                                         'Validator'   : lambda value: isinstance(value,int) or value == 'legacy'},
+
+        'tz_localize'               : { 'Default'     : True,
+                                        'Validator'   : lambda value: isinstance(value,bool) },
     }
 
     _validate_vkwargs_dict(vkwargs)