Update

Author: phofl

doc/source/user_guide/io.rst

@@ -197,6 +197,14 @@ dtype : Type name or dict of column -> type, default ``None``
      Support for defaultdict was added. Specify a defaultdict as input where
      the default determines the dtype of the columns which are not explicitly
      listed.
+
+use_nullable_dtypes: bool = False
+    Whether or not to use nullable dtypes as default when reading data. If
+    set to True, nullable dtypes are used for all dtypes that have a nullable
+    implementation, even if no nulls are present.
+
+    .. versionadded:: 2.0
+
 engine : {``'c'``, ``'python'``, ``'pyarrow'``}
   Parser engine to use. The C and pyarrow engines are faster, while the python engine
   is currently more feature-complete. Multithreading is currently only supported by

pandas/_libs/parsers.pyx

@@ -1057,7 +1057,6 @@ cdef class TextReader:
                     self._free_na_set(na_hashset)
 
             # don't try to upcast EAs
-            print(col_dtype)
             if (
                 na_count > 0 and not is_extension_array_dtype(col_dtype)
                 or self.use_nullable_dtypes

pandas/io/parsers/base_parser.py

@@ -735,7 +735,7 @@ def _infer_types(self, values, na_values, cast_type, try_num_bool: bool = True):
             else:
                 if use_nullable_dtypes:
                     if result_mask is None:
-                        result_mask = np.zeros(result.shape, dtype="bool")
+                        result_mask = np.zeros(result.shape, dtype=np.bool_)
 
                     if is_integer_dtype(result):
                         result = IntegerArray(result, result_mask)