feat: add dividends_annual property in Portfolio like dividends_annua…

…l property in AssetList.

main.py

@@ -6,6 +6,12 @@
 # ef.plot_cml(rf_return=0.15, y_axe="cagr")
 # plt.show()
 
-pf = ok.Portfolio(["SPY.US", "BND.US"], weights=[.5, .5], rebalancing_period="monthly")
-pf.wealth_index_with_assets.plot()
-plt.show()
+#pf = ok.Portfolio(["SPY.US", "BND.US"], weights=[.5, .5], rebalancing_period="monthly")
+#pf.wealth_index_with_assets.plot()
+#plt.show()
+
+
+import matplotlib.pyplot as plt
+pf = ok.Portfolio(['SPY.US', 'BND.US'], ccy='USD', last_date='07-2021', rebalancing_period="monthly")
+pf.dividends_annual.plot(kind='bar')
+plt.show()

okama/portfolio.py

@@ -822,6 +822,25 @@ def dividend_yield(self) -> pd.Series:
         div_yield_series.rename(self.symbol, inplace=True)
         return div_yield_series
 
+    @property
+    def dividends_annual(self) -> pd.DataFrame:
+        """
+        Return calendar year dividends sum time series for each asset.
+
+        Returns
+        -------
+        DataFrame
+            Annual dividends time series for each asset.
+
+        Examples
+        --------
+        >>> import matplotlib.pyplot as plt
+        >>> pf = ok.Portfolio(['SPY.US', 'BND.US'], ccy='USD', last_date='07-2021')
+        >>> pf.dividends_annual.plot(kind='bar')
+        >>> plt.show()
+        """
+        return self._get_assets_dividends().resample("Y").sum()
+
     @property
     def real_mean_return(self) -> float:
         """