resolves series.py issue pandas-dev#33327

Author: Vipul Rai

pandas/core/series.py

@@ -4661,7 +4661,8 @@ def to_timestamp(self, freq=None, how="start", copy=True) -> "Series":
         if copy:
             new_values = new_values.copy()
 
-        assert isinstance(self.index, (ABCDatetimeIndex, ABCPeriodIndex))
+        if not isinstance(self.index, (ABCDatetimeIndex, ABCPeriodIndex)):
+            raise TypeError(f"unsupported Type {self.index}")
         new_index = self.index.to_timestamp(freq=freq, how=how)
         return self._constructor(new_values, index=new_index).__finalize__(
             self, method="to_timestamp"
@@ -4688,7 +4689,8 @@ def to_period(self, freq=None, copy=True) -> "Series":
         if copy:
             new_values = new_values.copy()
 
-        assert isinstance(self.index, ABCDatetimeIndex)
+        if not isinstance(self.index, ABCDatetimeIndex):
+            raise TypeError(f"unsupported Type {self.index}")
         new_index = self.index.to_period(freq=freq)
         return self._constructor(new_values, index=new_index).__finalize__(
             self, method="to_period"