> As I code Python, I find myself falling back on Bash to handle basic OS > tasks. How do you gurus deal with Python --> Bash conflicts? > > For example, if I wish to test if a file exists, I might do > > test = Popen('[ -f file-i-want-to-test-for ]') > > But the moment I invoke Bash for a test, I must deal with the fact that > Bash returns a zero for true and a non-zero for false. But in Python, > zero is false and non-zero is true. So if the file exists, the variable > 'test' will be zero since that is what was returned by Bash. But if I > want to test the variable for the existence of the file, I have to test > the opposite: 'if not test:' because Python sees the zero as False. > > Does it become second nature to work with these conflicts? Or do you > find it more expedient bypass the OS shell and work almost exclusively > with Python?
try >>> import os.path >>> os.path.exists(path) or >>> os.path.isfile(file_name) http://docs.python.org/library/os.path.html > > > Ray > _______________________________________________ > Tutor maillist - Tutor@python.org > To unsubscribe or change subscription options: > http://mail.python.org/mailman/listinfo/tutor > > _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor