def open(self):
if self.filename is None:
raise IOError("No filename specified")
if not os.path.exists(self.filename):
raise IOError("Cannot find file '%s'" % self.filename)
self.sheet = None
if self._data is not None:
self.sheet = self._data
else:
try:
self.sheet = ExcelSpreadsheet(self.filename, ctype=self.ctype)
except pyutilib.common.ApplicationError:
raise
