reading xslx returns incorrect data due to bug in openpyxl load_workbook being called with use_iterators=True

[ruidc]

The situation is described in https://bitbucket.org/ericgazoni/openpyxl/issue/124/rawcellis_date-returns-false-positive
and results in datetime being returned instead of float causing incorrect data.

Could this method argument be exposed to the ExcelFile init with a default of True?

using False will work around the issue, presumably at the cost of performance.
Iteration code would then be needed in pandas ExcelFile._parse_xlsx

... As this bug has existed for months in openpyxl without comment and code is still described as "very raw" in openpyxl

https://bitbucket.org/ericgazoni/openpyxl/src/0082a961cf8b/openpyxl/reader/iter_worksheet.py#cl-27

Alternatively, if xlrd 0.8.0 is released with xlsx support, pandas could use that instead.

If you provide a test case, I'll take a look.
xlrd 0.9.0 is out with py3 support, need to do some work there anyway.

[ruidc]

So will pandas switch to using xlrd in preference of openpyxl?
I'll see if I can prepare a simple test case.

Don't know yet. it's actually python3 support in xlwt which would be helpful.

[ruidc]

sample xlsx file and code to reproduce here:
https://bitbucket.org/ruidc/openpyxl/commits/2cc76b66a0543b145a2eedd7860b7e0ef143c4c7

[dieterv77]

I added a pull request to openpyxl to fix this issue there:
https://bitbucket.org/ericgazoni/openpyxl/pull-request/31/fix-issue-124-use-same-check-for-dates-in/diff

Don't know about making xlrd>= 0.9.0 required in 0.11, punting to 0.12, unless
someone disagrees.

[jtratner]

@y-p @ruidc is this resolved now? I think it's covered by using xlrd, right?

[ruidc]

Indeed it is (at least when recent xlrd is used). Thanks.