On typecheck, calling strip() on a value of unknown type fails
Created originally on Bitbucket by ramn_se
File "...site-packages/openpyxl-1.5.8-py2.6.egg/openpyxl/cell.py", line 253, in data_type_for_value elif value.strip() in self.ERROR_CODES: AttributeError: 'list' object has no attribute 'strip'