. `49 <https://github.com/pyexcel/pyexcel-io/issues/49>`_, support additional options when detecting float values in csv format. default_float_nan, ignore_nan_text
. Issue `45 <https://github.com/pyexcel/pyexcel-io/issues/45>`_, csv reader throws exception because google app engine does not support mmap. People who are not working with google app engine, need not to take this update. Enjoy your Christmas break.