Adapt existing tests for arbitrary freq PeriodIndex, args formatting updated

Author: JoElfner

pandas/plotting/_timeseries.py

@@ -282,7 +282,7 @@ def _maybe_convert_index(ax, data):
         if isinstance(data.index, ABCDatetimeIndex):
             data = data.to_period(freq=freq)
         elif isinstance(data.index, ABCPeriodIndex):
-            data.index = data.index.asfreq(freq)
+            data.index = data.index.asfreq(freq=freq)
     return data
 
 

pandas/tests/plotting/test_datetimelike.py

@@ -211,7 +211,7 @@ def check_format_of_first_point(ax, expected_string):
     @pytest.mark.slow
     def test_line_plot_period_series(self):
         for s in self.period_ser:
-            _check_plot_works(s.plot, s.index.freq)
+            _check_plot_works(s.plot, s.index.freq.rule_code)
 
     @pytest.mark.slow
     def test_line_plot_datetime_series(self):
@@ -221,7 +221,8 @@ def test_line_plot_datetime_series(self):
     @pytest.mark.slow
     def test_line_plot_period_frame(self):
         for df in self.period_df:
-            _check_plot_works(df.plot, df.index.freq)
+            freq = df.index.asfreq(df.index.freq.rule_code).freq
+            _check_plot_works(df.plot, freq)
 
     @pytest.mark.slow
     def test_line_plot_datetime_frame(self):