Add **kwargs back into astype method

Author: makbigc

pandas/core/generic.py

@@ -5776,7 +5776,7 @@ def _to_dict_of_blocks(self, copy=True):
             for k, v, in self._data.to_dict(copy=copy).items()
         }
 
-    def astype(self, dtype, copy=True, errors="raise"):
+    def astype(self, dtype, copy=True, errors="raise", **kwargs):
         """
         Cast a pandas object to a specified dtype ``dtype``.
 
@@ -5799,6 +5799,8 @@ def astype(self, dtype, copy=True, errors="raise"):
 
             .. versionadded:: 0.20.0
 
+        **kwargs : keyword arguments to pass on to the constructor
+
         Returns
         -------
         casted : same type as caller
@@ -5884,7 +5886,7 @@ def astype(self, dtype, copy=True, errors="raise"):
                         "the key in Series dtype mappings."
                     )
                 new_type = dtype[self.name]
-                return self.astype(new_type, copy, errors)
+                return self.astype(new_type, copy, errors, **kwargs)
 
             for col_name in dtype.keys():
                 if col_name not in self:
@@ -5896,7 +5898,9 @@ def astype(self, dtype, copy=True, errors="raise"):
             for col_name, col in self.items():
                 if col_name in dtype:
                     results.append(
-                        col.astype(dtype=dtype[col_name], copy=copy, errors=errors)
+                        col.astype(
+                            dtype=dtype[col_name], copy=copy, errors=errors, **kwargs
+                        )
                     )
                 else:
                     results.append(results.append(col.copy() if copy else col))
@@ -5911,7 +5915,9 @@ def astype(self, dtype, copy=True, errors="raise"):
 
         else:
             # else, only a single dtype is given
-            new_data = self._data.astype(dtype=dtype, copy=copy, errors=errors)
+            new_data = self._data.astype(
+                dtype=dtype, copy=copy, errors=errors, **kwargs
+            )
             return self._constructor(new_data).__finalize__(self)
 
         # GH 19920: retain column metadata after concat