Update core.py - add pandas3.0 compatibility

1. Adopted ranaroussi#375 fixes on resample
2. modify df["col"].ffill(inplace=True) to df["col"] = df["col"].ffill()

Author: finiya

quantstats/_plotting/core.py

@@ -290,11 +290,9 @@ def plot_timeseries(
                 benchmark = benchmark.cumsum()
 
     if resample:
-        returns = returns.resample(resample)
-        returns = returns.last() if compound is True else returns.sum(axis=0)
+        returns = returns.resample(resample).last() if compound else returns.resample(resample).sum()
         if isinstance(benchmark, _pd.Series):
-            benchmark = benchmark.resample(resample)
-            benchmark = benchmark.last() if compound is True else benchmark.sum(axis=0)
+            benchmark = benchmark.resample(resample).last() if compound else benchmark.resample(resample).sum()
     # ---------------
 
     fig, ax = _plt.subplots(figsize=figsize)
@@ -1013,16 +1011,16 @@ def plot_distribution(
     apply_fnc = _stats.comp if compounded else _np.sum
 
     port["Weekly"] = port["Daily"].resample("W-MON").apply(apply_fnc)
-    port["Weekly"].ffill(inplace=True)
+    port["Weekly"] = port["Weekly"].ffill()
 
     port["Monthly"] = port["Daily"].resample("ME").apply(apply_fnc)
-    port["Monthly"].ffill(inplace=True)
+    port["Monthly"] = port["Monthly"].ffill()
 
     port["Quarterly"] = port["Daily"].resample("QE").apply(apply_fnc)
-    port["Quarterly"].ffill(inplace=True)
+    port["Quarterly"] = port["Quarterly"].ffill()
 
     port["Yearly"] = port["Daily"].resample("YE").apply(apply_fnc)
-    port["Yearly"].ffill(inplace=True)
+    port["Yearly"] = port["Yearly"].ffill()
 
     fig, ax = _plt.subplots(figsize=figsize)
     ax.spines["top"].set_visible(False)