Decouple xlrd reading from ExcelFile class (#24423)

Author: WillAyd

pandas/io/excel.py

@@ -358,23 +358,16 @@ def read_excel(io,
  **kwds)
 
 
-class ExcelFile(object):
- """
- Class for parsing tabular excel sheets into DataFrame objects.
- Uses xlrd. See read_excel for more documentation
-
- Parameters
- ----------
- io : string, path object (pathlib.Path or py._path.local.LocalPath),
- file-like object or xlrd workbook
- If a string or path object, expected to be a path to xls or xlsx file
- engine : string, default None
- If io is not a buffer or path, this must be set to identify io.
- Acceptable values are None or xlrd
- """
+class _XlrdReader(object):
 
- def __init__(self, io, **kwds):
+ def __init__(self, filepath_or_buffer):
+ """Reader using xlrd engine.
 
+ Parameters
+ ----------
+ filepath_or_buffer : string, path object or Workbook
+ Object to be parsed.
+ """
  err_msg = "Install xlrd >= 1.0.0 for Excel support"
 
  try:
@@ -386,46 +379,39 @@ def __init__(self, io, **kwds):
  raise ImportError(err_msg +
  ". Current version " + xlrd.__VERSION__)
 
- # could be a str, ExcelFile, Book, etc.
- self.io = io
- # Always a string
- self._io = _stringify_path(io)
-
- engine = kwds.pop('engine', None)
-
- if engine is not None and engine != 'xlrd':
- raise ValueError("Unknown engine: {engine}".format(engine=engine))
-
- # If io is a url, want to keep the data as bytes so can't pass
- # to get_filepath_or_buffer()
- if _is_url(self._io):
- io = _urlopen(self._io)
- elif not isinstance(self.io, (ExcelFile, xlrd.Book)):
- io, _, _, _ = get_filepath_or_buffer(self._io)
-
- if engine == 'xlrd' and isinstance(io, xlrd.Book):
- self.book = io
- elif not isinstance(io, xlrd.Book) and hasattr(io, "read"):
+ # If filepath_or_buffer is a url, want to keep the data as bytes so
+ # can't pass to get_filepath_or_buffer()
+ if _is_url(filepath_or_buffer):
+ filepath_or_buffer = _urlopen(filepath_or_buffer)
+ elif not isinstance(filepath_or_buffer, (ExcelFile, xlrd.Book)):
+ filepath_or_buffer, _, _, _ = get_filepath_or_buffer(
+ filepath_or_buffer)
+
+ if isinstance(filepath_or_buffer, xlrd.Book):
+ self.book = filepath_or_buffer
+ elif not isinstance(filepath_or_buffer, xlrd.Book) and hasattr(
+ filepath_or_buffer, "read"):
  # N.B. xlrd.Book has a read attribute too
- if hasattr(io, 'seek'):
+ if hasattr(filepath_or_buffer, 'seek'):
  try:
  # GH 19779
- io.seek(0)
+ filepath_or_buffer.seek(0)
  except UnsupportedOperation:
  # HTTPResponse does not support seek()
  # GH 20434
  pass
 
- data = io.read()
+ data = filepath_or_buffer.read()
  self.book = xlrd.open_workbook(file_contents=data)
- elif isinstance(self._io, compat.string_types):
- self.book = xlrd.open_workbook(self._io)
+ elif isinstance(filepath_or_buffer, compat.string_types):
+ self.book = xlrd.open_workbook(filepath_or_buffer)
  else:
  raise ValueError('Must explicitly set engine if not passing in'
  ' buffer or path for io.')
 
- def __fspath__(self):
- return self._io
+ @property
+ def sheet_names(self):
+ return self.book.sheet_names()
 
  def parse(self,
  sheet_name=0,
@@ -434,12 +420,13 @@ def parse(self,
  index_col=None,
  usecols=None,
  squeeze=False,
- converters=None,
+ dtype=None,
  true_values=None,
  false_values=None,
  skiprows=None,
  nrows=None,
  na_values=None,
+ verbose=False,
  parse_dates=False,
  date_parser=None,
  thousands=None,
@@ -448,72 +435,9 @@ def parse(self,
  convert_float=True,
  mangle_dupe_cols=True,
  **kwds):
- """
- Parse specified sheet(s) into a DataFrame
-
- Equivalent to read_excel(ExcelFile, ...) See the read_excel
- docstring for more info on accepted parameters
- """
-
- # Can't use _deprecate_kwarg since sheetname=None has a special meaning
- if is_integer(sheet_name) and sheet_name == 0 and 'sheetname' in kwds:
- warnings.warn("The `sheetname` keyword is deprecated, use "
- "`sheet_name` instead", FutureWarning, stacklevel=2)
- sheet_name = kwds.pop("sheetname")
- elif 'sheetname' in kwds:
- raise TypeError("Cannot specify both `sheet_name` "
- "and `sheetname`. Use just `sheet_name`")
-
- return self._parse_excel(sheet_name=sheet_name,
- header=header,
- names=names,
- index_col=index_col,
- usecols=usecols,
- squeeze=squeeze,
- converters=converters,
- true_values=true_values,
- false_values=false_values,
- skiprows=skiprows,
- nrows=nrows,
- na_values=na_values,
- parse_dates=parse_dates,
- date_parser=date_parser,
- thousands=thousands,
- comment=comment,
- skipfooter=skipfooter,
- convert_float=convert_float,
- mangle_dupe_cols=mangle_dupe_cols,
- **kwds)
-
- def _parse_excel(self,
- sheet_name=0,
- header=0,
- names=None,
- index_col=None,
- usecols=None,
- squeeze=False,
- dtype=None,
- true_values=None,
- false_values=None,
- skiprows=None,
- nrows=None,
- na_values=None,
- verbose=False,
- parse_dates=False,
- date_parser=None,
- thousands=None,
- comment=None,
- skipfooter=0,
- convert_float=True,
- mangle_dupe_cols=True,
- **kwds):
 
  _validate_header_arg(header)
 
- if 'chunksize' in kwds:
- raise NotImplementedError("chunksize keyword of read_excel "
- "is not implemented")
-
  from xlrd import (xldate, XL_CELL_DATE,
  XL_CELL_ERROR, XL_CELL_BOOLEAN,
  XL_CELL_NUMBER)
@@ -563,7 +487,7 @@ def _parse_cell(cell_contents, cell_typ):
  sheets = sheet_name
  ret_dict = True
  elif sheet_name is None:
- sheets = self.sheet_names
+ sheets = self.book.sheet_names()
  ret_dict = True
  else:
  sheets = [sheet_name]
@@ -678,9 +602,111 @@ def _parse_cell(cell_contents, cell_typ):
  else:
  return output[asheetname]
 
+
+class ExcelFile(object):
+ """
+ Class for parsing tabular excel sheets into DataFrame objects.
+ Uses xlrd. See read_excel for more documentation
+
+ Parameters
+ ----------
+ io : string, path object (pathlib.Path or py._path.local.LocalPath),
+ file-like object or xlrd workbook
+ If a string or path object, expected to be a path to xls or xlsx file.
+ engine : string, default None
+ If io is not a buffer or path, this must be set to identify io.
+ Acceptable values are None or ``xlrd``.
+ """
+
+ _engines = {
+ 'xlrd': _XlrdReader,
+ }
+
+ def __init__(self, io, engine=None):
+ if engine is None:
+ engine = 'xlrd'
+ if engine not in self._engines:
+ raise ValueError("Unknown engine: {engine}".format(engine=engine))
+
+ # could be a str, ExcelFile, Book, etc.
+ self.io = io
+ # Always a string
+ self._io = _stringify_path(io)
+
+ self._reader = self._engines[engine](self._io)
+
+ def __fspath__(self):
+ return self._io
+
+ def parse(self,
+ sheet_name=0,
+ header=0,
+ names=None,
+ index_col=None,
+ usecols=None,
+ squeeze=False,
+ converters=None,
+ true_values=None,
+ false_values=None,
+ skiprows=None,
+ nrows=None,
+ na_values=None,
+ parse_dates=False,
+ date_parser=None,
+ thousands=None,
+ comment=None,
+ skipfooter=0,
+ convert_float=True,
+ mangle_dupe_cols=True,
+ **kwds):
+ """
+ Parse specified sheet(s) into a DataFrame
+
+ Equivalent to read_excel(ExcelFile, ...) See the read_excel
+ docstring for more info on accepted parameters
+ """
+
+ # Can't use _deprecate_kwarg since sheetname=None has a special meaning
+ if is_integer(sheet_name) and sheet_name == 0 and 'sheetname' in kwds:
+ warnings.warn("The `sheetname` keyword is deprecated, use "
+ "`sheet_name` instead", FutureWarning, stacklevel=2)
+ sheet_name = kwds.pop("sheetname")
+ elif 'sheetname' in kwds:
+ raise TypeError("Cannot specify both `sheet_name` "
+ "and `sheetname`. Use just `sheet_name`")
+
+ if 'chunksize' in kwds:
+ raise NotImplementedError("chunksize keyword of read_excel "
+ "is not implemented")
+
+ return self._reader.parse(sheet_name=sheet_name,
+ header=header,
+ names=names,
+ index_col=index_col,
+ usecols=usecols,
+ squeeze=squeeze,
+ converters=converters,
+ true_values=true_values,
+ false_values=false_values,
+ skiprows=skiprows,
+ nrows=nrows,
+ na_values=na_values,
+ parse_dates=parse_dates,
+ date_parser=date_parser,
+ thousands=thousands,
+ comment=comment,
+ skipfooter=skipfooter,
+ convert_float=convert_float,
+ mangle_dupe_cols=mangle_dupe_cols,
+ **kwds)
+
+ @property
+ def book(self):
+ return self._reader.book
+
  @property
  def sheet_names(self):
- return self.book.sheet_names()
+ return self._reader.sheet_names
 
  def close(self):
  """close io if necessary"""