TYP: check_untyped_defs io.sas.sasreader (#30659)

Author: simonjayhawkins

pandas/io/sas/sas7bdat.py

@@ -26,6 +26,7 @@
 from pandas.io.common import get_filepath_or_buffer
 from pandas.io.sas._sas import Parser
 import pandas.io.sas.sas_constants as const
+from pandas.io.sas.sasreader import ReaderBase
 
 
 class _subheader_pointer:
@@ -37,7 +38,7 @@ class _column:
 
 
 # SAS7BDAT represents a SAS data file in SAS7BDAT format.
-class SAS7BDATReader(abc.Iterator):
+class SAS7BDATReader(ReaderBase, abc.Iterator):
     """
     Read SAS files in SAS7BDAT format.
 

pandas/io/sas/sas_xport.py

@@ -19,6 +19,7 @@
 import pandas as pd
 
 from pandas.io.common import get_filepath_or_buffer
+from pandas.io.sas.sasreader import ReaderBase
 
 _correct_line1 = (
     "HEADER RECORD*******LIBRARY HEADER RECORD!!!!!!!"
@@ -239,7 +240,7 @@ def _parse_float_vec(vec):
     return ieee
 
 
-class XportReader(abc.Iterator):
+class XportReader(ReaderBase, abc.Iterator):
     __doc__ = _xport_reader_doc
 
     def __init__(

pandas/io/sas/sasreader.py

@@ -1,9 +1,27 @@
 """
 Read SAS sas7bdat or xport files.
 """
+
+from abc import ABCMeta, abstractmethod
+
 from pandas.io.common import stringify_path
 
 
+# TODO: replace with Protocol in Python 3.8
+class ReaderBase(metaclass=ABCMeta):
+    """
+    Protocol for XportReader and SAS7BDATReader classes.
+    """
+
+    @abstractmethod
+    def read(self, nrows=None):
+        pass
+
+    @abstractmethod
+    def close(self):
+        pass
+
+
 def read_sas(
     filepath_or_buffer,
     format=None,
@@ -62,6 +80,7 @@ def read_sas(
         else:
             raise ValueError("unable to infer format of SAS file")
 
+    reader: ReaderBase
     if format.lower() == "xport":
         from pandas.io.sas.sas_xport import XportReader
 

setup.cfg

@@ -291,9 +291,6 @@ check_untyped_defs=False
 [mypy-pandas.io.sas.sas7bdat]
 check_untyped_defs=False
 
-[mypy-pandas.io.sas.sasreader]
-check_untyped_defs=False
-
 [mypy-pandas.io.stata]
 check_untyped_defs=False