On my system (mac 10.6.8, python2.7.5, gcc 4.2.1) the following code works fine:
from openpyxl import Workbook
from os import system
wb = Workbook()
outputf = 'test.xlsx'
wb.save(outputf)
# see below *
system('open ' + outputf)
(see comments: I lost the bet. The error was somewhere else in the code and has nothing to do with system('open ' + whatever))
I bet there is something wrong with permissions in your new file on your system. Maybe you add
(docu)
st = os.stat(outputf)
os.chmod(outputf, st.st_mode | stat.stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO)
(with input from other link)
in the code instead of my commentary ('# see below *') Then it should be possible to open it by everyone and everything...
If it works, this is a workaround. There is a difference between our system and I do not know what difference. If not, well, I did not test it on my system (because I did not have a problem with the code), write a comment and I might play with the settings or maybe someone else has an idea.
Btw.: In a terminal in your folder: What output gives 'ls -l excelfilename' after execution of the python code? What programming environment do you use? I start the program via 'python2.7 pythonscript.py' in the terminal.