diff --git a/pandas/io/clipboard/__init__.py b/pandas/io/clipboard/__init__.py
index 63dd40a229dfc..40452b41998df 100644
--- a/pandas/io/clipboard/__init__.py
+++ b/pandas/io/clipboard/__init__.py
@@ -95,8 +95,8 @@ def _stringifyText(text):
     acceptedTypes = (str, int, float, bool)
     if not isinstance(text, acceptedTypes):
         raise PyperclipException(
-            "only str, int, float, and bool values"
-            "can be copied to the clipboard, not".format(text.__class__.__name__)
+            f"only str, int, float, and bool values"
+            f"can be copied to the clipboard, not {text.__class__.__name__}"
         )
     return str(text)
 
diff --git a/pandas/io/date_converters.py b/pandas/io/date_converters.py
index ab64bc14344f1..7fdca2d65b05d 100644
--- a/pandas/io/date_converters.py
+++ b/pandas/io/date_converters.py
@@ -57,8 +57,8 @@ def _check_columns(cols):
     for i, n in enumerate(map(len, tail)):
         if n != N:
             raise AssertionError(
-                "All columns must have the same length: {0}; "
-                "column {1} has length {2}".format(N, i, n)
+                f"All columns must have the same length: {N}; "
+                f"column {i} has length {n}"
             )
 
     return N
diff --git a/pandas/io/excel/_odfreader.py b/pandas/io/excel/_odfreader.py
index 3a67f8306fff1..97556f9685001 100644
--- a/pandas/io/excel/_odfreader.py
+++ b/pandas/io/excel/_odfreader.py
@@ -61,7 +61,7 @@ def get_sheet_by_name(self, name: str):
             if table.getAttribute("name") == name:
                 return table
 
-        raise ValueError("sheet {} not found".format(name))
+        raise ValueError(f"sheet {name} not found")
 
     def get_sheet_data(self, sheet, convert_float: bool) -> List[List[Scalar]]:
         """Parse an ODF Table into a list of lists
diff --git a/pandas/io/excel/_openpyxl.py b/pandas/io/excel/_openpyxl.py
index d8f5da5ab5bc6..d0d6096a4425e 100644
--- a/pandas/io/excel/_openpyxl.py
+++ b/pandas/io/excel/_openpyxl.py
@@ -46,7 +46,8 @@ def save(self):
     @classmethod
     def _convert_to_style(cls, style_dict):
         """
-        converts a style_dict to an openpyxl style object
+        Converts a style_dict to an openpyxl style object.
+
         Parameters
         ----------
         style_dict : style dictionary to convert
@@ -72,7 +73,8 @@ def _convert_to_style(cls, style_dict):
     def _convert_to_style_kwargs(cls, style_dict):
         """
         Convert a style_dict to a set of kwargs suitable for initializing
-        or updating-on-copy an openpyxl v2 style object
+        or updating-on-copy an openpyxl v2 style object.
+
         Parameters
         ----------
         style_dict : dict
@@ -83,6 +85,7 @@ def _convert_to_style_kwargs(cls, style_dict):
                 'alignment'
                 'number_format'
                 'protection'
+
         Returns
         -------
         style_kwargs : dict
@@ -107,7 +110,8 @@ def _convert_to_style_kwargs(cls, style_dict):
     @classmethod
     def _convert_to_color(cls, color_spec):
         """
-        Convert ``color_spec`` to an openpyxl v2 Color object
+        Convert ``color_spec`` to an openpyxl v2 Color object.
+
         Parameters
         ----------
         color_spec : str, dict
@@ -120,6 +124,7 @@ def _convert_to_color(cls, color_spec):
                 'tint'
                 'index'
                 'type'
+
         Returns
         -------
         color : openpyxl.styles.Color
@@ -135,7 +140,8 @@ def _convert_to_color(cls, color_spec):
     @classmethod
     def _convert_to_font(cls, font_dict):
         """
-        Convert ``font_dict`` to an openpyxl v2 Font object
+        Convert ``font_dict`` to an openpyxl v2 Font object.
+
         Parameters
         ----------
         font_dict : dict
@@ -154,6 +160,7 @@ def _convert_to_font(cls, font_dict):
                 'outline'
                 'shadow'
                 'condense'
+
         Returns
         -------
         font : openpyxl.styles.Font
@@ -185,11 +192,13 @@ def _convert_to_stop(cls, stop_seq):
         """
         Convert ``stop_seq`` to a list of openpyxl v2 Color objects,
         suitable for initializing the ``GradientFill`` ``stop`` parameter.
+
         Parameters
         ----------
         stop_seq : iterable
             An iterable that yields objects suitable for consumption by
             ``_convert_to_color``.
+
         Returns
         -------
         stop : list of openpyxl.styles.Color
@@ -200,7 +209,8 @@ def _convert_to_stop(cls, stop_seq):
     @classmethod
     def _convert_to_fill(cls, fill_dict):
         """
-        Convert ``fill_dict`` to an openpyxl v2 Fill object
+        Convert ``fill_dict`` to an openpyxl v2 Fill object.
+
         Parameters
         ----------
         fill_dict : dict
@@ -216,6 +226,7 @@ def _convert_to_fill(cls, fill_dict):
                 'top'
                 'bottom'
                 'stop'
+
         Returns
         -------
         fill : openpyxl.styles.Fill
@@ -262,7 +273,8 @@ def _convert_to_fill(cls, fill_dict):
     @classmethod
     def _convert_to_side(cls, side_spec):
         """
-        Convert ``side_spec`` to an openpyxl v2 Side object
+        Convert ``side_spec`` to an openpyxl v2 Side object.
+
         Parameters
         ----------
         side_spec : str, dict
@@ -270,6 +282,7 @@ def _convert_to_side(cls, side_spec):
             of the following keys (or their synonyms).
                 'style' ('border_style')
                 'color'
+
         Returns
         -------
         side : openpyxl.styles.Side
@@ -295,7 +308,8 @@ def _convert_to_side(cls, side_spec):
     @classmethod
     def _convert_to_border(cls, border_dict):
         """
-        Convert ``border_dict`` to an openpyxl v2 Border object
+        Convert ``border_dict`` to an openpyxl v2 Border object.
+
         Parameters
         ----------
         border_dict : dict
@@ -311,6 +325,7 @@ def _convert_to_border(cls, border_dict):
                 'diagonalUp' ('diagonalup')
                 'diagonalDown' ('diagonaldown')
                 'outline'
+
         Returns
         -------
         border : openpyxl.styles.Border
@@ -335,7 +350,8 @@ def _convert_to_border(cls, border_dict):
     @classmethod
     def _convert_to_alignment(cls, alignment_dict):
         """
-        Convert ``alignment_dict`` to an openpyxl v2 Alignment object
+        Convert ``alignment_dict`` to an openpyxl v2 Alignment object.
+
         Parameters
         ----------
         alignment_dict : dict
diff --git a/pandas/io/excel/_xlwt.py b/pandas/io/excel/_xlwt.py
index fe3d0a208de6a..996ae1caa14c8 100644
--- a/pandas/io/excel/_xlwt.py
+++ b/pandas/io/excel/_xlwt.py
@@ -77,7 +77,9 @@ def write_cells(
                 wks.write(startrow + cell.row, startcol + cell.col, val, style)
 
     @classmethod
-    def _style_to_xlwt(cls, item, firstlevel=True, field_sep=",", line_sep=";"):
+    def _style_to_xlwt(
+        cls, item, firstlevel: bool = True, field_sep=",", line_sep=";"
+    ) -> str:
         """helper which recursively generate an xlwt easy style string
         for example:
 
@@ -117,6 +119,7 @@ def _style_to_xlwt(cls, item, firstlevel=True, field_sep=",", line_sep=";"):
     def _convert_to_style(cls, style_dict, num_format_str=None):
         """
         converts a style_dict to an xlwt style object
+
         Parameters
         ----------
         style_dict : style dictionary to convert
diff --git a/pandas/io/feather_format.py b/pandas/io/feather_format.py
index dd6519275ad15..d9e88f42c2ef2 100644
--- a/pandas/io/feather_format.py
+++ b/pandas/io/feather_format.py
@@ -10,7 +10,7 @@
 from pandas.io.common import _stringify_path
 
 
-def to_feather(df, path):
+def to_feather(df: DataFrame, path):
     """
     Write a DataFrame to the feather-format
 
diff --git a/pandas/io/formats/csvs.py b/pandas/io/formats/csvs.py
index e25862537cbfc..f0493036b934a 100644
--- a/pandas/io/formats/csvs.py
+++ b/pandas/io/formats/csvs.py
@@ -327,7 +327,7 @@ def _save(self):
 
             self._save_chunk(start_i, end_i)
 
-    def _save_chunk(self, start_i, end_i):
+    def _save_chunk(self, start_i: int, end_i: int):
 
         data_index = self.data_index
 
diff --git a/pandas/io/formats/excel.py b/pandas/io/formats/excel.py
index b9c847ad64c57..cd0889044094f 100644
--- a/pandas/io/formats/excel.py
+++ b/pandas/io/formats/excel.py
@@ -63,8 +63,9 @@ def __init__(self, inherited=None):
 
     compute_css = CSSResolver()
 
-    def __call__(self, declarations_str):
-        """Convert CSS declarations to ExcelWriter style
+    def __call__(self, declarations_str: str):
+        """
+        Convert CSS declarations to ExcelWriter style.
 
         Parameters
         ----------
@@ -279,6 +280,7 @@ def build_font(self, props):
                 if "text-shadow" in props
                 else None
             ),
+            # FIXME: dont leave commented-out
             # 'vertAlign':,
             # 'charset': ,
             # 'scheme': ,
@@ -665,7 +667,7 @@ def _format_hierarchical_rows(self):
         for cell in self._generate_body(gcolidx):
             yield cell
 
-    def _generate_body(self, coloffset):
+    def _generate_body(self, coloffset: int):
         if self.styler is None:
             styles = None
         else:
diff --git a/pandas/io/formats/latex.py b/pandas/io/formats/latex.py
index ca9db88ae7be4..6f903e770c86c 100644
--- a/pandas/io/formats/latex.py
+++ b/pandas/io/formats/latex.py
@@ -11,8 +11,8 @@
 
 
 class LatexFormatter(TableFormatter):
-    """ Used to render a DataFrame to a LaTeX tabular/longtable environment
-    output.
+    """
+    Used to render a DataFrame to a LaTeX tabular/longtable environment output.
 
     Parameters
     ----------
@@ -106,18 +106,19 @@ def pad_empties(x):
             # Get rid of old multiindex column and add new ones
             strcols = out + strcols[1:]
 
-        column_format = self.column_format
-        if column_format is None:
+        if self.column_format is None:
             dtypes = self.frame.dtypes._values
             column_format = "".join(map(get_col_type, dtypes))
             if self.fmt.index:
                 index_format = "l" * self.frame.index.nlevels
                 column_format = index_format + column_format
-        elif not isinstance(column_format, str):  # pragma: no cover
+        elif not isinstance(self.column_format, str):  # pragma: no cover
             raise AssertionError(
                 "column_format must be str or unicode, "
                 "not {typ}".format(typ=type(column_format))
             )
+        else:
+            column_format = self.column_format
 
         if self.longtable:
             self._write_longtable_begin(buf, column_format)
@@ -265,7 +266,7 @@ def _format_multirow(
 
     def _print_cline(self, buf: IO[str], i: int, icol: int) -> None:
         """
-        Print clines after multirow-blocks are finished
+        Print clines after multirow-blocks are finished.
         """
         for cl in self.clinebuf:
             if cl[0] == i:
@@ -273,7 +274,7 @@ def _print_cline(self, buf: IO[str], i: int, icol: int) -> None:
         # remove entries that have been written to buffer
         self.clinebuf = [x for x in self.clinebuf if x[0] != i]
 
-    def _write_tabular_begin(self, buf, column_format):
+    def _write_tabular_begin(self, buf, column_format: str):
         """
         Write the beginning of a tabular environment or
         nested table/tabular environments including caption and label.
@@ -283,11 +284,10 @@ def _write_tabular_begin(self, buf, column_format):
         buf : string or file handle
             File path or object. If not specified, the result is returned as
             a string.
-        column_format : str, default None
+        column_format : str
             The columns format as specified in `LaTeX table format
             <https://en.wikibooks.org/wiki/LaTeX/Tables>`__ e.g 'rcl'
             for 3 columns
-
         """
         if self.caption is not None or self.label is not None:
             # then write output in a nested table/tabular environment
@@ -327,7 +327,7 @@ def _write_tabular_end(self, buf):
         else:
             pass
 
-    def _write_longtable_begin(self, buf, column_format):
+    def _write_longtable_begin(self, buf, column_format: str):
         """
         Write the beginning of a longtable environment including caption and
         label if provided by user.
@@ -337,11 +337,10 @@ def _write_longtable_begin(self, buf, column_format):
         buf : string or file handle
             File path or object. If not specified, the result is returned as
             a string.
-        column_format : str, default None
+        column_format : str
             The columns format as specified in `LaTeX table format
             <https://en.wikibooks.org/wiki/LaTeX/Tables>`__ e.g 'rcl'
             for 3 columns
-
         """
         buf.write("\\begin{{longtable}}{{{fmt}}}\n".format(fmt=column_format))
 
diff --git a/pandas/io/html.py b/pandas/io/html.py
index 9a368907b65aa..ed2b21994fdca 100644
--- a/pandas/io/html.py
+++ b/pandas/io/html.py
@@ -57,7 +57,7 @@ def _importers():
 _RE_WHITESPACE = re.compile(r"[\r\n]+|\s{2,}")
 
 
-def _remove_whitespace(s, regex=_RE_WHITESPACE):
+def _remove_whitespace(s: str, regex=_RE_WHITESPACE) -> str:
     """
     Replace extra whitespace inside of a string with a single space.
 
@@ -65,8 +65,7 @@ def _remove_whitespace(s, regex=_RE_WHITESPACE):
     ----------
     s : str or unicode
         The string from which to remove extra whitespace.
-
-    regex : regex
+    regex : re.Pattern
         The regular expression to use to remove extra whitespace.
 
     Returns
@@ -253,7 +252,8 @@ def _text_getter(self, obj):
         raise AbstractMethodError(self)
 
     def _parse_td(self, obj):
-        """Return the td elements from a row element.
+        """
+        Return the td elements from a row element.
 
         Parameters
         ----------
@@ -600,7 +600,7 @@ def _build_doc(self):
         )
 
 
-def _build_xpath_expr(attrs):
+def _build_xpath_expr(attrs) -> str:
     """Build an xpath expression to simulate bs4's ability to pass in kwargs to
     search for attributes when using the lxml parser.
 
@@ -810,7 +810,8 @@ def _data_to_frame(**kwargs):
 
 
 def _parser_dispatch(flavor):
-    """Choose the parser based on the input flavor.
+    """
+    Choose the parser based on the input flavor.
 
     Parameters
     ----------
@@ -850,7 +851,7 @@ def _parser_dispatch(flavor):
     return _valid_parsers[flavor]
 
 
-def _print_as_set(s):
+def _print_as_set(s) -> str:
     return "{" + "{arg}".format(arg=", ".join(pprint_thing(el) for el in s)) + "}"
 
 
diff --git a/pandas/io/json/_json.py b/pandas/io/json/_json.py
index 0a8f275cf54a9..26a3248262f9a 100644
--- a/pandas/io/json/_json.py
+++ b/pandas/io/json/_json.py
@@ -711,7 +711,7 @@ def _get_data_from_filepath(self, filepath_or_buffer):
 
         return data
 
-    def _combine_lines(self, lines):
+    def _combine_lines(self, lines) -> str:
         """
         Combines a list of JSON objects into one JSON object.
         """
@@ -1169,7 +1169,7 @@ def _try_convert_dates(self):
             convert_dates = []
         convert_dates = set(convert_dates)
 
-        def is_ok(col):
+        def is_ok(col) -> bool:
             """
             Return if this col is ok to try for a date parse.
             """
diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index ee08e2abb2289..03eb8570e436e 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -92,7 +92,7 @@ def _ensure_str(name):
 Term = Expr
 
 
-def _ensure_term(where, scope_level):
+def _ensure_term(where, scope_level: int):
     """
     ensure that the where is a Term or a list of Term
     this makes sure that we are capturing the scope of variables
@@ -252,7 +252,7 @@ def to_hdf(
     complevel=None,
     complib=None,
     append=None,
-    **kwargs
+    **kwargs,
 ):
     """ store this object, close it if we opened it """
 
@@ -271,7 +271,7 @@ def to_hdf(
         f(path_or_buf)
 
 
-def read_hdf(path_or_buf, key=None, mode="r", **kwargs):
+def read_hdf(path_or_buf, key=None, mode: str = "r", **kwargs):
     """
     Read from the store, close it if we opened it.
 
@@ -340,8 +340,8 @@ def read_hdf(path_or_buf, key=None, mode="r", **kwargs):
 
     if mode not in ["r", "r+", "a"]:
         raise ValueError(
-            "mode {0} is not allowed while performing a read. "
-            "Allowed modes are r, r+ and a.".format(mode)
+            f"mode {mode} is not allowed while performing a read. "
+            f"Allowed modes are r, r+ and a."
         )
     # grab the scope
     if "where" in kwargs:
@@ -406,7 +406,7 @@ def read_hdf(path_or_buf, key=None, mode="r", **kwargs):
         raise
 
 
-def _is_metadata_of(group, parent_group):
+def _is_metadata_of(group, parent_group) -> bool:
     """Check if a given group is a metadata group for a given parent_group."""
     if group._v_depth <= parent_group._v_depth:
         return False
@@ -466,7 +466,13 @@ class HDFStore:
     """
 
     def __init__(
-        self, path, mode=None, complevel=None, complib=None, fletcher32=False, **kwargs
+        self,
+        path,
+        mode=None,
+        complevel=None,
+        complib=None,
+        fletcher32: bool = False,
+        **kwargs,
     ):
 
         if "format" in kwargs:
@@ -577,7 +583,7 @@ def items(self):
 
     iteritems = items
 
-    def open(self, mode="a", **kwargs):
+    def open(self, mode: str = "a", **kwargs):
         """
         Open the file in the specified mode
 
@@ -615,19 +621,19 @@ def open(self, mode="a", **kwargs):
 
         try:
             self._handle = tables.open_file(self._path, self._mode, **kwargs)
-        except (IOError) as e:  # pragma: no cover
-            if "can not be written" in str(e):
+        except IOError as err:  # pragma: no cover
+            if "can not be written" in str(err):
                 print("Opening {path} in read-only mode".format(path=self._path))
                 self._handle = tables.open_file(self._path, "r", **kwargs)
             else:
                 raise
 
-        except (ValueError) as e:
+        except ValueError as err:
 
             # trap PyTables >= 3.1 FILE_OPEN_POLICY exception
             # to provide an updated message
-            if "FILE_OPEN_POLICY" in str(e):
-                e = ValueError(
+            if "FILE_OPEN_POLICY" in str(err):
+                err = ValueError(
                     "PyTables [{version}] no longer supports opening multiple "
                     "files\n"
                     "even in read-only mode on this HDF5 version "
@@ -641,14 +647,14 @@ def open(self, mode="a", **kwargs):
                     )
                 )
 
-            raise e
+            raise err
 
-        except (Exception) as e:
+        except Exception as err:
 
             # trying to read from a non-existent file causes an error which
             # is not part of IOError, make it one
-            if self._mode == "r" and "Unable to open/create file" in str(e):
-                raise IOError(str(e))
+            if self._mode == "r" and "Unable to open/create file" in str(err):
+                raise IOError(str(err))
             raise
 
     def close(self):
@@ -660,7 +666,7 @@ def close(self):
         self._handle = None
 
     @property
-    def is_open(self):
+    def is_open(self) -> bool:
         """
         return a boolean indicating whether the file is open
         """
@@ -668,7 +674,7 @@ def is_open(self):
             return False
         return bool(self._handle.isopen)
 
-    def flush(self, fsync=False):
+    def flush(self, fsync: bool = False):
         """
         Force all buffered modifications to be written to disk.
 
@@ -719,8 +725,8 @@ def select(
         columns=None,
         iterator=False,
         chunksize=None,
-        auto_close=False,
-        **kwargs
+        auto_close: bool = False,
+        **kwargs,
     ):
         """
         Retrieve pandas object stored in file, optionally based on where criteria.
@@ -824,10 +830,11 @@ def select_as_multiple(
         stop=None,
         iterator=False,
         chunksize=None,
-        auto_close=False,
-        **kwargs
+        auto_close: bool = False,
+        **kwargs,
     ):
-        """ Retrieve pandas objects from multiple tables
+        """
+        Retrieve pandas objects from multiple tables.
 
         Parameters
         ----------
@@ -839,6 +846,8 @@ def select_as_multiple(
         stop  : integer (defaults to None), row number to stop selection
         iterator : boolean, return an iterator, default False
         chunksize : nrows to include in iteration, return an iterator
+        auto_close : bool, default False
+            Should automatically close the store when finished.
 
         Raises
         ------
@@ -860,7 +869,7 @@ def select_as_multiple(
                 stop=stop,
                 iterator=iterator,
                 chunksize=chunksize,
-                **kwargs
+                **kwargs,
             )
 
         if not isinstance(keys, (list, tuple)):
@@ -1262,27 +1271,28 @@ def copy(
         self,
         file,
         mode="w",
-        propindexes=True,
+        propindexes: bool = True,
         keys=None,
         complib=None,
         complevel=None,
-        fletcher32=False,
+        fletcher32: bool = False,
         overwrite=True,
     ):
-        """ copy the existing store to a new file, upgrading in place
-
-            Parameters
-            ----------
-            propindexes: restore indexes in copied file (defaults to True)
-            keys       : list of keys to include in the copy (defaults to all)
-            overwrite  : overwrite (remove and replace) existing nodes in the
-                new store (default is True)
-            mode, complib, complevel, fletcher32 same as in HDFStore.__init__
+        """
+        Copy the existing store to a new file, updating in place.
 
-            Returns
-            -------
-            open file handle of the new store
+        Parameters
+        ----------
+        propindexes: bool, default True
+            Restore indexes in copied file.
+        keys       : list of keys to include in the copy (defaults to all)
+        overwrite  : overwrite (remove and replace) existing nodes in the
+            new store (default is True)
+        mode, complib, complevel, fletcher32 same as in HDFStore.__init__
 
+        Returns
+        -------
+        open file handle of the new store
         """
         new_store = HDFStore(
             file, mode=mode, complib=complib, complevel=complevel, fletcher32=fletcher32
@@ -1302,7 +1312,7 @@ def copy(
                 data = self.select(k)
                 if s.is_table:
 
-                    index = False
+                    index = False  # type: Union[bool, list]
                     if propindexes:
                         index = [a.name for a in s.axes if a.is_indexed]
                     new_store.append(
@@ -1317,7 +1327,7 @@ def copy(
 
         return new_store
 
-    def info(self):
+    def info(self) -> str:
         """
         Print detailed information on the store.
 
@@ -1478,7 +1488,7 @@ def _write_to_group(
         append=False,
         complib=None,
         encoding=None,
-        **kwargs
+        **kwargs,
     ):
         group = self.get_node(key)
 
@@ -1550,13 +1560,16 @@ class TableIterator:
         nrows : the rows to iterate on
         start : the passed start value (default is None)
         stop  : the passed stop value (default is None)
-        iterator : boolean, whether to use the default iterator
+        iterator : bool, default False
+            Whether to use the default iterator.
         chunksize : the passed chunking value (default is 50000)
         auto_close : boolean, automatically close the store at the end of
             iteration, default is False
         kwargs : the passed kwargs
         """
 
+    chunksize: Optional[int]
+
     def __init__(
         self,
         store,
@@ -1566,7 +1579,7 @@ def __init__(
         nrows,
         start=None,
         stop=None,
-        iterator=False,
+        iterator: bool = False,
         chunksize=None,
         auto_close=False,
     ):
@@ -1619,7 +1632,7 @@ def close(self):
         if self.auto_close:
             self.store.close()
 
-    def get_result(self, coordinates=False):
+    def get_result(self, coordinates: bool = False):
 
         #  return the actual iterator
         if self.chunksize is not None:
@@ -1676,7 +1689,7 @@ def __init__(
         freq=None,
         tz=None,
         index_name=None,
-        **kwargs
+        **kwargs,
     ):
         self.values = values
         self.kind = kind
@@ -1708,13 +1721,13 @@ def set_name(self, name, kind_attr=None):
 
         return self
 
-    def set_axis(self, axis):
+    def set_axis(self, axis: int):
         """ set the axis over which I index """
         self.axis = axis
 
         return self
 
-    def set_pos(self, pos):
+    def set_pos(self, pos: int):
         """ set the position of this column in the Table """
         self.pos = pos
         if pos is not None and self.typ is not None:
@@ -1736,23 +1749,23 @@ def __repr__(self) -> str:
             )
         )
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         """ compare 2 col items """
         return all(
             getattr(self, a, None) == getattr(other, a, None)
             for a in ["name", "cname", "axis", "pos"]
         )
 
-    def __ne__(self, other):
+    def __ne__(self, other) -> bool:
         return not self.__eq__(other)
 
     @property
-    def is_indexed(self):
+    def is_indexed(self) -> bool:
         """ return whether I am an indexed column """
         try:
             return getattr(self.table.cols, self.cname).is_indexed
         except AttributeError:
-            False
+            return False
 
     def copy(self):
         new_self = copy.copy(self)
@@ -1767,7 +1780,9 @@ def infer(self, handler):
         new_self.read_metadata(handler)
         return new_self
 
-    def convert(self, values, nan_rep, encoding, errors, start=None, stop=None):
+    def convert(
+        self, values: np.ndarray, nan_rep, encoding, errors, start=None, stop=None
+    ):
         """ set the values from this selection: take = take ownership """
 
         # values is a recarray
@@ -1961,7 +1976,7 @@ class GenericIndexCol(IndexCol):
     """ an index which is not represented in the data of the table """
 
     @property
-    def is_indexed(self):
+    def is_indexed(self) -> bool:
         return False
 
     def convert(self, values, nan_rep, encoding, errors, start=None, stop=None):
@@ -2042,7 +2057,7 @@ def __init__(
         meta=None,
         metadata=None,
         block=None,
-        **kwargs
+        **kwargs,
     ):
         super().__init__(values=values, kind=kind, typ=typ, cname=cname, **kwargs)
         self.dtype = None
@@ -2497,7 +2512,7 @@ def __init__(self, parent, group, encoding=None, errors="strict", **kwargs):
         self.set_version()
 
     @property
-    def is_old_version(self):
+    def is_old_version(self) -> bool:
         return self.version[0] <= 0 and self.version[1] <= 10 and self.version[2] < 1
 
     def set_version(self):
@@ -2515,7 +2530,7 @@ def pandas_type(self):
         return _ensure_decoded(getattr(self.group._v_attrs, "pandas_type", None))
 
     @property
-    def format_type(self):
+    def format_type(self) -> str:
         return "fixed"
 
     def __repr__(self) -> str:
@@ -2590,7 +2605,7 @@ def storable(self):
         return self.group
 
     @property
-    def is_exists(self):
+    def is_exists(self) -> bool:
         return False
 
     @property
@@ -2647,7 +2662,7 @@ class GenericFixed(Fixed):
     attributes = []  # type: List[str]
 
     # indexer helpders
-    def _class_to_alias(self, cls):
+    def _class_to_alias(self, cls) -> str:
         return self._index_type_map.get(cls, "")
 
     def _alias_to_class(self, alias):
@@ -2700,7 +2715,7 @@ def validate_read(self, kwargs):
         return kwargs
 
     @property
-    def is_exists(self):
+    def is_exists(self) -> bool:
         return True
 
     def set_attrs(self):
@@ -2908,14 +2923,14 @@ def read_index_node(self, node, start=None, stop=None):
                     data, kind, encoding=self.encoding, errors=self.errors
                 ),
                 dtype=object,
-                **kwargs
+                **kwargs,
             )
         else:
             index = factory(
                 _unconvert_index(
                     data, kind, encoding=self.encoding, errors=self.errors
                 ),
-                **kwargs
+                **kwargs,
             )
 
         index.name = name
@@ -2931,7 +2946,7 @@ def write_array_empty(self, key, value):
         getattr(self.group, key)._v_attrs.value_type = str(value.dtype)
         getattr(self.group, key)._v_attrs.shape = value.shape
 
-    def _is_empty_array(self, shape):
+    def _is_empty_array(self, shape) -> bool:
         """Returns true if any axis is zero length."""
         return any(x == 0 for x in shape)
 
@@ -3210,7 +3225,7 @@ def table_type_short(self):
         return self.table_type.split("_")[0]
 
     @property
-    def format_type(self):
+    def format_type(self) -> str:
         return "table"
 
     def __repr__(self) -> str:
@@ -3309,7 +3324,7 @@ def nrows_expected(self):
         return np.prod([i.cvalues.shape[0] for i in self.index_axes])
 
     @property
-    def is_exists(self):
+    def is_exists(self) -> bool:
         """ has this table been created """
         return "table" in self.group
 
@@ -3335,12 +3350,12 @@ def axes(self):
         return itertools.chain(self.index_axes, self.values_axes)
 
     @property
-    def ncols(self):
+    def ncols(self) -> int:
         """ the number of total columns in the values axes """
         return sum(len(a.values) for a in self.values_axes)
 
     @property
-    def is_transposed(self):
+    def is_transposed(self) -> bool:
         return False
 
     @property
@@ -3378,7 +3393,7 @@ def values_cols(self):
         """ return a list of my values cols """
         return [i.cname for i in self.values_axes]
 
-    def _get_metadata_path(self, key):
+    def _get_metadata_path(self, key) -> str:
         """ return the metadata pathname for this key """
         return "{group}/meta/{key}/meta".format(group=self.group._v_pathname, key=key)
 
@@ -3572,9 +3587,19 @@ def create_index(self, columns=None, optlevel=None, kind=None):
                         )
                     v.create_index(**kw)
 
-    def read_axes(self, where, **kwargs):
-        """create and return the axes sniffed from the table: return boolean
-        for success
+    def read_axes(self, where, **kwargs) -> bool:
+        """
+        Create the axes sniffed from the table.
+
+        Parameters
+        ----------
+        where : ???
+        **kwargs
+
+        Returns
+        -------
+        bool
+            Indicates success.
         """
 
         # validate the version
@@ -3654,7 +3679,7 @@ def create_axes(
         nan_rep=None,
         data_columns=None,
         min_itemsize=None,
-        **kwargs
+        **kwargs,
     ):
         """ create and return the axes
         legacy tables create an indexable column, indexable index,
@@ -3941,7 +3966,7 @@ def process_filter(field, filt):
         return obj
 
     def create_description(
-        self, complib=None, complevel=None, fletcher32=False, expectedrows=None
+        self, complib=None, complevel=None, fletcher32: bool = False, expectedrows=None
     ):
         """ create the description of the table from the axes & values """
 
@@ -4104,7 +4129,7 @@ def write(
         chunksize=None,
         expectedrows=None,
         dropna=False,
-        **kwargs
+        **kwargs,
     ):
 
         if not append and self.is_exists:
@@ -4340,7 +4365,7 @@ class AppendableFrameTable(AppendableTable):
     obj_type = DataFrame  # type: Type[Union[DataFrame, Series]]
 
     @property
-    def is_transposed(self):
+    def is_transposed(self) -> bool:
         return self.index_axes[0].axis == 1
 
     def get_object(self, obj):
@@ -4411,7 +4436,7 @@ class AppendableSeriesTable(AppendableFrameTable):
     storage_obj_type = DataFrame
 
     @property
-    def is_transposed(self):
+    def is_transposed(self) -> bool:
         return False
 
     def get_object(self, obj):
@@ -4547,7 +4572,7 @@ def read(self, **kwargs):
         return df
 
 
-def _reindex_axis(obj, axis, labels, other=None):
+def _reindex_axis(obj, axis: int, labels: Index, other=None):
     ax = obj._get_axis(axis)
     labels = ensure_index(labels)
 
@@ -4562,7 +4587,7 @@ def _reindex_axis(obj, axis, labels, other=None):
     if other is not None:
         labels = ensure_index(other.unique()).intersection(labels, sort=False)
     if not labels.equals(ax):
-        slicer = [slice(None, None)] * obj.ndim
+        slicer = [slice(None, None)] * obj.ndim  # type: List[Union[slice, Index]]
         slicer[axis] = labels
         obj = obj.loc[tuple(slicer)]
     return obj
@@ -4588,7 +4613,7 @@ def _get_tz(tz):
     return zone
 
 
-def _set_tz(values, tz, preserve_UTC=False, coerce=False):
+def _set_tz(values, tz, preserve_UTC: bool = False, coerce: bool = False):
     """
     coerce the values to a DatetimeIndex if tz is set
     preserve the input shape if possible
@@ -4597,7 +4622,7 @@ def _set_tz(values, tz, preserve_UTC=False, coerce=False):
     ----------
     values : ndarray
     tz : string/pickled tz object
-    preserve_UTC : boolean,
+    preserve_UTC : bool,
         preserve the UTC of the result
     coerce : if we do not have a passed timezone, coerce to M8[ns] ndarray
     """
@@ -4842,7 +4867,7 @@ def _unconvert_string_array(data, nan_rep=None, encoding=None, errors="strict"):
     return data.reshape(shape)
 
 
-def _maybe_convert(values, val_kind, encoding, errors):
+def _maybe_convert(values: np.ndarray, val_kind, encoding, errors):
     if _need_convert(val_kind):
         conv = _get_converter(val_kind, encoding, errors)
         # conv = np.frompyfunc(conv, 1, 1)
@@ -4862,7 +4887,7 @@ def _get_converter(kind, encoding, errors):
         raise ValueError("invalid kind {kind}".format(kind=kind))
 
 
-def _need_convert(kind):
+def _need_convert(kind) -> bool:
     kind = _ensure_decoded(kind)
     if kind in ("datetime", "datetime64", "string"):
         return True
diff --git a/pandas/io/sas/sas_xport.py b/pandas/io/sas/sas_xport.py
index ea26a9b8efdbf..2f2dbdbc76215 100644
--- a/pandas/io/sas/sas_xport.py
+++ b/pandas/io/sas/sas_xport.py
@@ -143,7 +143,7 @@
 """
 
 
-def _parse_date(datestr):
+def _parse_date(datestr: str) -> datetime:
     """ Given a date in xport format, return Python date. """
     try:
         # e.g. "16FEB11:10:07:55"
@@ -152,11 +152,11 @@ def _parse_date(datestr):
         return pd.NaT
 
 
-def _split_line(s, parts):
+def _split_line(s: str, parts):
     """
     Parameters
     ----------
-    s: string
+    s: str
         Fixed-length string to split
     parts: list of (name, length) pairs
         Used to break up string, name '_' will be filtered from output.
@@ -402,7 +402,7 @@ def _read_header(self):
     def __next__(self):
         return self.read(nrows=self._chunksize or 1)
 
-    def _record_count(self):
+    def _record_count(self) -> int:
         """
         Get number of records in file.