do not try to catch args if there are only kwargs, added ideas (commented out) for further removing reader selection logic out of ExcelFile class

Author: davidovitch

pandas/io/excel.py

@@ -106,7 +106,7 @@ def open_workbook(self, *args, **kwargs):
  if isinstance(self._open_workbook, type(None)):
  self.load_engine()
  # just in case the user passes an already opened workbook of io_class
- if isinstance(args[0], self.io_class):
+ if len(args) > 0 and isinstance(args[0], self.io_class):
  return args[0]
  return self._open_workbook(*args, **kwargs)
 
@@ -122,14 +122,21 @@ def is_ext(self, path):
  else:
  return False
 
- def is_type(self, io):
+ def is_type(self, io):#, engine=None):
  """Verify if the io type is supported by the reader. If the reader is
  not installed, return False.
  """
  if isinstance(io, type(None)):
  return False
  elif isinstance(io, self.io_class):
  return True
+# elif self.engine == engine:
+# return True
+# elif isinstance(io, compat.string_types):
+# if self.is_ext(io):
+# return True
+# else:
+# return False
  else:
  return False
 
@@ -164,6 +171,24 @@ def _load_engine(self):
  self._open_workbook = xlrd.open_workbook
  self.io_class = xlrd.Book
 
+# def open_workbook(self, *args, **kwargs):
+# """Explicitely load the engine again (and trigger an ImportError in the
+# process) if _open_workbook is set to None.
+# """
+# # try to load the engine again and raise import error if required
+# if isinstance(self._open_workbook, type(None)):
+# self.load_engine()
+# io = args[0]
+# # just in case the user passes an already opened workbook of io_class
+# if isinstance(io, self.io_class):
+# return io
+# # N.B. xlrd.Book has a read attribute too
+# elif hasattr(io, "read"):
+# data = io.read()
+# return self._open_workbook(file_contents=data)
+#
+# return self._open_workbook(*args, **kwargs)
+
 
 class EZODFFile(BaseFile):
  """File reader class for ODF spreadsheets (depends on ezodf)