openpyxl leaks file handle in py py implementation
*Created originally on Bitbucket by [simoscofield (C. W.)](https://bitbucket.org/%7B9a7670a9-7be2-4ece-b16b-7c5a68d5de43%7D/)* Here is the code to reproduce: ``` #!python import openpyxl import psutil proc = psutil.Process() open_files_l1 = proc.open_files() print("number of open file handles: %s" % len(open_files_l1)) b = openpyxl.load_workbook( filename="test.xlsx", data_only=True, read_only=True) b.close() open_files_l2 = proc.open_files() print("number of open file handles: %s" % len(open_files_l2)) print(open_files_l2) assert len(open_files_l1) == len(open_files_l2) ``` And here is the result ``` #!bash $ python test.py number of open file handles: 0 number of open file handles: 2 [popenfile(path='/Users//github/pyexcel-xlsx/test.xlsx', fd=5), popenfile(path='/Users//github/pyexcel-xlsx/test.xlsx', fd=6)] Traceback (most recent call last): File "test.py", line 14, in <module> assert len(open_files_l1) == len(open_files_l2) AssertionError $ python Python 2.7.13 (1aa2d8e03cdf, Mar 31 2017, 10:20:53) [PyPy 5.7.1 with GCC 4.2.1 Compatible Apple LLVM 5.1 (clang-503.0.40)] on darwin Type "help", "copyright", "credits" or "license" for more information. ``` *Attachments:* [test.xlsx](/uploads/f656fb53da8bf57f97157fe1908e2cd3/test.xlsx)
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